A recent research project has unveiled the actions animals take after pretending to be dead as a strategy to evade predators and the circumstances surrounding this behavior.
A recent research study conducted by scientists from the University of Bristol has uncovered what happens to animals after they feign death to escape from predators and the context of this behavior.
Many creatures, as a final defense, go completely still when approached by a predator.
This behavior is so prevalent that it is often described with terms like “playing possum.” Interestingly, humans may also exhibit this response in extreme situations.
Past research, conducted by the same team on antlion larvae, indicated that these insects become immobile after being individually handled.
At one point, the larvae need to be weighed, which can be quite challenging due to their tiny size. If they move on the scale, it complicates the task of measuring their weight accurately.
However, when the antlion larvae were carefully placed onto the scale, they remained completely still long enough for their weight to be recorded properly.
Emeritus Professor Nigel Franks from the University of Bristol’s School of Biological Sciences, who oversaw the study, stated: “We aimed to explore this ‘death-feigning’ behavior and discovered that the length of time an individual antlion stays motionless is entirely random for each one.”
“This was validated by examining the durations of post-contact immobility across a large sample of antlions. The data revealed an exponential distribution, similar to the unpredictability of radioactive atoms changing states, while the overall population’s behavior follows a predictable pattern.”
The study indicates that the antlions’ tactic of remaining still in plain view is probably advantageous. A predator that picks up and releases an antlion larvae cannot predict how long it will take before the prey moves again and becomes recognizable. In fact, one antlion studied stayed motionless for over an hour.
Even though the timing of when a still antlion will resume activity is unpredictable, it does not guarantee that the predator will leave in search of other prey.
The researchers were curious about what happens to animals after they pretend to be dead. In this new study, they found that the actions of antlions post-feigning death vary based on their circumstances.
As burrowing creatures, antlion larvae might instinctively look for safety by digging into the soft ground where they usually create their pits. However, there’s a chance that a predator could drop an antlion onto a hard surface that prevents it from escaping by burying itself.
Utilizing advanced automated video tracking technology to analyze the sporadic movement of individual antlions on various surfaces, the researchers determined that an antlion’s post-motionless behavior depends on the available escape options.
Professor Franks commented: “Our research might be the first to explore what happens after animals play dead, demonstrating that their responses are context-dependent. It involves a trade-off. This work opens the door to examining post-contact behaviors in the vast array of animals exhibiting death feigning, thanatosis, or what we prefer to call post-contact immobility.”
