Reducing Human Directed Aggression from Snakes in Human Care
11 Motivators We Can Address Right Now to Stop Getting Bit by Captive Snakes
(CW: Photos of snakes in aggressive postures + photo of snake eating)
Human-directed aggression from snakes in human care is often categorized in one of two categories: feeding response or a defensive reaction. There are, however, many potential motivators. By identifying and understanding the function of the behavior, we can address the behavior in the least invasive way, causing less duress for both snake and caretaker.
Understandably, most aggressive behavior occurs in the context of entering the snake’s living space and/or removing them from their captive habitat for handling, medical care, husbandry, or feeding. These interactions are not completely unavoidable for an animal living in human care.
It is helpful to remember that all behavior is driven by a combination of instinct and consequences. With snakes, we frequently make the mistake of over-emphasizing the role of instinct and undervaluing the role of consequences. Snakes are always learning and adapting their behavior to fit their current environment.
Let’s look at some of the stimuli and scenarios that might shape and influence their learning history and thus their current and future behavior.
Species adaptations and individual genetics. What does the natural history of this animal look like? We want to go beyond looking at the behavior of captive animals and look at what their wild counterparts do. Where do they spend their time? What do they eat? How do they hunt? When do they hunt? When are they active? Having this data can help us to interact with them in less aversive and threatening ways and reduce stress stacking—which is when multiple low-level stressors experienced at the same time can motivate a stronger reaction than if one of those stressors was experienced at a time. Providing species-appropriate opportunities to get up high, burrow in loose substrate, soak, hide or even just have adequate flight distance all help to reduce overall stress levels. When the animal is at a lower level of stress when you start the interaction, this allows you more leeway before their stress levels become severe.
While most animal caretakers will be somewhat aware of what is needed to create a safe living space in which the species can survive, next you want to consider how the individual might differ from their conspecifics. Providing as many opportunities for choice as you can help you to determine your specific animal’s individual needs. Sometimes, in a species that likes to burrow, an individual will like to climb. Or, in a species that likes to climb, an individual will show a preference for swimming. Behavioral diversity is fine and perfectly normal, especially for animals that are adapting their behavior to living in human care. Remember genetics, evolution and ultimate motivators are only part of the picture. Their individual learning history is going to be the biggest factor for behavior that you get in a captive setting. Provide many opportunities within the captive environment for the behaviors that will help the animal cope with and adapt to living in human care.
When planning the living space, do not forget the space outside of the animal habitat. Think about the activity the happens in the room that the habitat occupies, the ambient light cycles of the room, lower frequency sounds and music, any odors or scents, and the ambient temperature and humidity. Think about these first in the context of the animal’s natural history and then in the context of the individual as you learn their preferences and behavior patterns. Think about how the outer environment—the space outside the glass or tub--shapes the animal’s behavior. When you see them active, does the behavior match with similar motivators in their wild counterparts. Are they investigating something in the habitat? Foraging? Seeking water or to thermoregulate? Or are there other antecedents in the outer environment like music playing with a lot of bass, a room full of people, lights on and off at random times, or a new smell in the room? While for some individuals these things could be interesting novel experiences, for others they could raise stress to a more severe level. Most of these things can be habituated to over time but can impact your training interactions—and remember all interactions are training interactions because animals are always learning. Behavior that they learn and that is functioning for them when they are under more stress can be rehearsed and continue as long as the behavior continues to function for them.
Illness or injury. When an animal is unwell, this will also affect their overall stress level. This can cause them to react in ways that they might necessarily do otherwise. Always observe your animal both when walking up to their living space and when you ultimately enter their living space. Do you see any overt signs of discomfort or illness? When was their last health checkup? If there is any chance that poor health is affecting their behavior, you will want to address this first before progressing your training. You may want to make interim management modifications so that you can properly care for them throughout the treatment. Using tools like using a voluntary shift box and/or covering part of the habitat with cloth or paper or using a board to block visual and give extra space between you and them when performing husbandry tasks can help to reduce stress and minimize rehearsing aggressive behavior during this time.
Overall hunger level and the frequency with which food is available. This can be challenging to gauge in human care. The animal’s overall hunger state cannot be determined by body score – meaning how fat or thin they are. A very hungry snake may hyperfocus more on movement and be more likely to strike indiscriminately. The same behavioral science applies to snakes as applies to all living things and this is true of most predators in all taxa. Think of watching large cat species try to catch and kill prey that is too big when they are very hungry. Hunger levels often will have a very visible effect on mental state, as evidenced by behavior. Remember when we are observing the environment for antecedents to the aggressive behavior, the internal state of the animal is included. When entering the space of a very hungry snake – whether due to shed cycle, seasonal variations, or diet restriction for health or medical reasons, we want to be mindful of this and modify how we interact with them and for how long. You will want to think about using tools, having a more hands-off approach, and giving the animal more space in whatever minimally invasive ways that you can do that.
Developmental stages and seasonal variations. Evolutionary adaptations do not account completely for behavior, but they are important. A younger animal has less learning history. This can be advantageous for us as caretakers because we can positively shape behavior from the beginning. These animals may also need more space and be more likely to try a variety of behaviors to see what works. They can be more likely to use fight or flight when faced with a stressful situation. They are also growing faster and assessing the level of hunger may be more challenging. Strive to not apply too much pressure too fast. In most cases, the instinct to flee vs fight will initially be stronger. It is when we start to take away the option to flee, either through continually applying pressure and moving closer even though they show signs of stress, or simply not having a big enough space that they can have adequate flight distance, that we will be more likely to see them start to use striking and biting.
When animals are older, they may be eating less frequently and their behavior patterns may change. Seasonal variations can impact behavior in a variety of ways as well, motivating hyper or hypo activity levels. When we see behavior change in a well-established animal and healthy snake, this is a good time to take a step back, offer more hands-off enrichment activities, give more space, and observe and take data. We can then adapt our training plan to their new behavior patterns and preferences.
Prior learning history – rehearsed behavior or lack of behavior. Sometimes aggressive behavior will continue even when the original motivator or threat has been removed. If this was due to a threat like forced handling for medical treatment, we may have to counter condition or habituate the antecedents that used to mean a threat was present. Simply no longer interacting in an aversive way may not end the behavior. If this learning history involves striking at the handler in the presence of food or a heightened hunger state, we may need to make the contingency to obtaining food more clear and predictable.
It is relatively common practice to introduce a cue that means food is not happening or accessible right now, as evidenced by the popularity of hook and tap training, but putting the food and feeding process on a predictable contingency and focusing on what you want the animal to do vs what you don’t want them to do can make the contingency more clear. This might look like introducing a target or station or offering food in a puzzle device. I’ll talk more about why below.
Shortened foraging patterns paired with highly recognizable and largely unvaried cues. Overall lack of full behavioral repertoire. Sensitization to cues. In human care, the foraging process for snakes has largely been reduced to smell food, see food, strike food, wrap food, consume food. This is quite different from wild counterparts who must learn to find the best hunting places, travel to those places, sit and wait in those places for sometimes up to a week, travel through burrows, climb up into trees, swim through water, avoid potential predators and size up and assess their own risk of being injured and or missing a strike before they do finally strike to catch their prey. While all snakes might not do all of these things, this is a wide behavioral repertoire and a lot of problem solving that we have essentially erased from captive care. While there were once multiple environmental cues that had to be learned and responded to before the actual strike and eat, in human care, there are generally very few.
In training multiple species of snakes, in multiple different types of captive environments from in private homes, classrooms, and retail spaces to within zoological facilities, it has been shown that snakes learn and modify their behavior extremely quickly. They quickly learn associations and how to access reinforcers. When we shorten their behavioral patterns that are required to obtain food, we are more likely to sensitize the cues that mean the food is coming. While a hunt might take hours or days or weeks in their native habitat, we are training them that they should be ready to strike as soon as they smell food. Other cues can become conditioned and generalized to mean be ready to strike as well, like opening the latch to the habitat, or even just the human caregiver walking towards the habitat. These captive routines are largely unvaried by the caretaker and learning history can include a lot of reinforcement for being immediately prepared to perform this last couple of behaviors in what would be a long foraging pattern naturally. This can build a very unnatural response to feeding in human care. This can lead to handler-directed aggression, especially if something happens that makes the path to food less clear – like an internal hunger state, heightened stress, or … change in contingency, which we will talk about next.
Extinction burst in an unclear contingency. It is widely documented that when a living thing cannot access a reinforcer in a way that they have previously learned to, that this can result in heightened stress and a burst of behavior that often includes aggression. While we might be aware that this can happen when we are consciously training and change our criteria, it can also happen when we are not mindfully training and the animal has learned what behaviors under what antecedents earn them reinforcement. When they cannot access the reinforcer, whether it is access, safety, food, or something else, this can lead to a burst of aggression. This does not have to be a fear response where they are in fight or flight but rather is born out of frustration. We should always attempt to gradually change contingencies to avoid this and keep our interactions minimally intrusive.
Extinction event driven behavior can be one of the motivators when we see aggressive behavior when we make changes to an operantly influenced routine that an animal is used to. While we might be inclined to dismiss this as a tantrum of sorts, it is important to be empathetic to how this might feel for the learner and try to minimize creating this scenario. This will result in a safer training interaction and less duress for both caretaker and snake.
Redirected aggression. While a snake might strike at the human caretaker or handler in this situation, the person may not be the intended target. In this case, something startles the snake that is not necessarily connected to the training interaction – a broom handle falling over and hitting the floor, another human entering the room, a dog barking, a tree branch swaying in the wind. These situations are not always avoidable, but we can do our best to set up a training area that is largely free of unintended consequences. As you build more contingencies with your snake, in more environments, you can start to habituate or counter-condition things that you know they might eventually encounter.
Difficulty reading body language. Added to the above challenges, as mammals who have bodies that are quite different than snakes, sometimes we just simply have miscommunications. Reading snake body language often does not come intuitively and is a learned skill. While there are various resources and classes available to learn this, it does take practice. When we can read when a snake subtly says no to something through their body language this can prevent a lot of human-directed aggression. Aggression is expensive for most living things and carries a risk that they may become injured or die. Usually, it is not the first reaction that a living thing will have to a perceived threat. By learning to communicate and listen in more nuanced ways to the animals in our care, we can dramatically reduce the occurrence of bites and injuries to humans.
The role of learned helplessness. While learned helplessness might be a term that is a little overused and is sometimes used incorrectly, it does occur. This occurs when an animal is presented with an aversive that it cannot control or get away from and they stop behaving in ways to try to get away from it. This does not change how they feel and they do not habituate in this scenario, in essence, they give up. Now, even if presented with a way to escape the aversive, they do not try. They do not run away and they do not aggress. One of the problems with it can be that an animal learns to stop fighting or reacting in one scenario/environment but this behavior is not generalized. So while you think you might have tamed or trained an animal to accept a certain interaction, it is very context-specific. If the antecedents change, you can see unexpected aggression.
Punishment fallout. Even if an animal does not go into a state of learned helplessness, we can see a fallout from punishment. This can include an animal that is less likely to try new behavior but an animal may also react aggressively when being punished or if they think that they are going to be punished. Punishment is anything that the learner finds aversive that happens within a learned contingency and consequently reduces the frequency of that behavior in the future. It does not have to be extreme or what we might deem as abusive. It is individual and a method we used with one individual can still motivate an aggressive response from a different individual.
Often, we use punishment for aggressive behavior as it is a behavior we want to stop but this can make the situation worse. We can also unintentionally punish, for example reaching out for a snake that is approaching us or putting a snake back in the enclosure that doesn’t want to go back. Sometimes we might even clamp down and hold a snake more firmly that is starting to act aggressively. We might be leery to put them down because we’ve been told that this will reinforce the behavior, but often the fallout from using punishment can be worse and have longstanding consequences on behavior and your relationship with that animal. These things can not only reduce some behaviors that we would want to see more of, but the snake can react with a strike or a bite and we might feel like this came “out of nowhere”.
Conclusion. I hope this information helps you to look at some of the potential functions of aggressive behavior, isolate the motivators, reinforcers, and punishers and move your training plan forward. When we look at the behavior as a response in an environment and not within the animal, it can open up so many more options for changing behavior in positive and low-stress ways. It also can give us a renewed sense of empathy for our learner.
Aggressive behavior from an animal can be frustrating, isolating and take an emotional toll on the caretaker, but it’s not something that we have to just accept and live with. By removing labels and unhelpful constructs and taking a methodical approach, we can find ways to improve choice, control and communication for both the learner and the caretaker. When we do so, we can reduce and eliminate aggressive behaviors, and replace them with more desirable behaviors, creating a safer and less stressful life for all involved. Acknowledgments: Many thanks to Hannah Branigan, Stephanie Edlund, Emily Strong, Dana McDonald, Peter Amelia, Dr. Eduardo Fernandez, and Alex Konold for their time and contributions to this post. Carrie Luann Davis (she/her) is an international animal training consultant, educator and innovator. She brings two decades of experience working as a professional animal trainer and zookeeper. She has worked for AZA accredited zoos including The Living Desert Zoo and Gardens and the San Diego Zoo as well as numerous nonprofit organizations, rescues, and animal sanctuaries. Carrie co-founded Reptelligence in 2013, an organization that strives to be a catalyst for introducing innovative enrichment options and accessible, choice based, minimally aversive training techniques for reptiles and other non-furred and non-feathered animals in human care. She is passionate about improving well-being for captive animals and their caretakers through both allowing and motivating a full expression of their individual behavioral repertoire. She lives in Joshua Tree, California, USA with two dogs, Skyla and Bam and an Australian Woma Python named Magnolia