Ever see a bug and then can’t shake the feeling that something is crawling on you? Apologies in advance, but this article may give you that sensation. Scientists invented the world’s smallest remote-controlled walking robot that is flea-sized. And they made a whole bunch of them, all in the shape of creepy crawlies like crabs, inch worms, and insects. While it’s a cool boost in technology, we can’t help but feel our skin crawling. Thanks to GizmodoOpens in a new tab for bringing these robots to our attention.
The crab robots are about the size a flea at half a millimeter across, or 1/50th of an inch. They can get that small because they don’t need batteries, wires, or electricity. Instead, the researchers used a technique inspired by children’s pop-up books.
They alternate between flat and three dimensional based on temperature. Rapidly changing between states gives them motion. Localized lasers create heat, which causes the material to turn, twist, and even walk and jump. Because they are so small, heating and cooling happens quickly.

The peer-reviewed journal Science Robotics published the research,Opens in a new tab including a series of videos of the robots in action. Last year, some of the same researchers created airborne microbotsOpens in a new tab that could disperse on the wind like seeds. There are many other tiny robots in development. Including microbots to deliver medicineOpens in a new tab inside the body. There’s even one made of slimeOpens in a new tab that is controlled by magnets.

Does the idea of a tiny, flea-sized robot crawling on you, or even inside of you, give you the heebie-jeebies? If so, it may be helpful to know that there are already millions of organisms at home both on and in your body. From your gut bacteria to mites on your eyelashes, we’re never alone. Or maybe that’s also a horrifying thought and not comforting at all.
Melissa is Nerdist’s science & technology staff writer. She also moderates “science of” panels at conventions and co-hosts Star WarsologiesOpens in a new tab, a podcast about science and Star Wars. Follow her on Twitter @melissatruthOpens in a new tab.