Robots can already walk our dogs. Why not put them to work catching pesky houseflies, too? University of Maine engineer Mohsen Shahinpoor is trying to do just that, with a mechanical bug killer modeled after the Venus flytrap. How does his predatory plantbot work? Here, three key questions:

How do Venus flytraps catch bugs?
The plants, which derive energy from digested flies and spiders, employ mouth-like leaves covered in tiny hairs. If an insect touches two different hairs within 20 seconds, the trapping motion is triggered. The leaves slam shut like a clam shell and capture the bug in a mere 100 milliseconds. Then it's lunchtime.

And how does this new robotic version work?
Shahinpoor's prototype replaces the ultra-sensitive plant hairs with a special polymer membrane coated in gold electrodes. When a bug lands on one of the device's "leaves," the "tiny voltage it generates triggers a larger power source to apply opposite charges to the leaves, making them attract one another and closing the trap," explains New Scientist.  

Will the future be full of killer, bug-eating robots?
Well, not quite. Shahinpoor's prototype "doesn't eat the bug," says Jack Loftus of Gizmodo. So the robot can't refuel itself — at least not yet. Regardless, a robot that can kill anything — even just a bug — is "alarming," says Rebecca Boyle at Popular Science. This model is "a major step on the path towards robots that can hunt, catch and digest their own meals."

Sources: GizmodoNew Scientist, Popular Science