The lifelike robot, built by a team from the University of California, Davis, can replicate two behaviors squirrels display when confronted by a rattlesnake.
Research by the late Donald Owings, professor of psychology at UC Davis, observed that rather than scamper off squirrels would approach a snake "head-first in an elongated posture, making flagging movements with their tails."
He also discovered their tails heat up, which is picked up by a snake's infrared sensor.
But in the wild there is no way to separate the "heat" and the "flagging," say researchers. And that's where the robot comes in.
Out in the field near San Jose, researchers set up "robosquirrel" and a video camera near a foraging snake before retreating out of sight.
The snakes observed appear to accept the robot as real, with one snake even biting the robot's head, according to researchers.
This doesn't happen often in the wild says Clark, because squirrels possess a "remarkable ability" to dodge a snake attack.
"Snakes will rarely strike a flagging adult squirrel, and if they do they almost always miss," said Rulon Clark, assistant professor of biology at San Diego State University.
It's still not clear why squirrels approach such a deadly predator, but Clark says they maybe trying to assess the nature of the threat. In some cases snakes will leave the area after an encounter.
"Robosquirrel" joins a growing list of robot creatures created by UC Davis which include a robot lizard -- used to study display behavior in anole lizards in the Puerto Rican jungle.
Another saw the use of a robot sage grouse hen to study their real-life mating habits.
