Antipredator Behavior in Pavement Ants, Tetramorium sp. E
Pavement ants, Tetramorium sp. E and antlions, Myrmeleontidae, compete with each other for survival. The interplay between the species suggests coevolution, an evolutionary arms race between predators and prey. Learning may be one way in which predators and prey are able to develop the ability to best their counterparts. Antlions are capable of learning to better prepare for prey; because ants are the main prey of antlions, they may correspondingly learn to avoid being captured. In this project, individual ants were placed in a bowl with an antlion pit and were given time to fall into the pit, get grabbed, and potentially escape. The pre-trial phase, in which an ant was placed in a bowl with an antlion pit for the first time, included conditions with and without the antlion present. In roughly 30% of trials, the ant escaped from the mandibles of the antlion and climbed out of the pit. The post-trial phase, in which the escapee was placed back into a bowl with an antlion pit, included conditions with and without the antlion present, as well as conditions in which ants were placed near a different pit than the one from which they escaped. These conditions permit evaluation of an ant’s ability to learn to avoid antlion pits as well as different methods by which an ant may learn: through odor cues, through visual memory of the pit, or by sensing an antlion’s presence. Ants that escaped from being grabbed by an antlion had a significantly longer latency to fall into the antlion’s pit when exposed again compared to ants that merely climbed in and out of the antlion’s pit. These data, when combined with data from several other control groups, suggest that ants learn to alter their behavior to avoid the antlions’ pits (and possible death) a second time.