In a research recently published this month in Biology Letters, scientists from the University of Bristol observed how a single antlion larva pretended to be dead for a surprising duration of 61 minutes.
Explaining the significance of this observation, scientists say it means that a predator will be unable to predict when a potential prey will move again, attract attention, and become a meal. The amount of time that an individual remains motionless is not only long but unpredictable which would eventually render the hungry predator impatient.
However, another downside of looking at this information is that the prey may be losing opportunities to get on with their lives if they remain motionless for too long. Hence, death-feigning might best be thought of as part of a dangerous game of hiding and seek in which the prey might gain most by faking death if other victims are easily available.
In a statement to the University of Bristol, the lead author of the paper, Professor Nigel R. Franks from the School of Biological Sciences said to imagine a person in a garden full of identical soft fruit bushes. The scientists go to the first bush. Initially, collecting and eating fruit is fast and easy, but as they eat all the fruits in the bush, finding more fruit gets difficult and more time-consuming. At some stage, the person should decide to go to another bush and begin again. Since a predator is inherently greedy, they would want to eat as many fruits as quickly as possible.
Franks explains that the marginal value theorem would show how long a person should spend time at each bush given that time will also be lost moving to the next bush.
The scientists used this approach to consider a small bird visiting patches of prominent antlion pits to show that antlion larvae that waste some of the predator’s time, by ‘playing dead’ if they are dropped, change the game significantly. The playing dead technique encourages the predator to search somewhere else.