Cockroaches get everywhere. There they are, somehow, against all odds, in that room that looked to be totally sealed from the outside world, in that cupboard you swore was tightly shut. Now, Kaushik Jayaram and Robert Full from the University of California, Berkeley have discovered the secret behind their feats of infiltration.

By confronting American cockroaches with an ever-narrower series of crevices, the duo found that although this insect typically stands 12 millimeters tall, it can squeeze through gaps of 3 millimeters—the height of two stacked U.S. pennies. It does this by squatting down and then compressing its body by half. It is the world’s worst Transformer: instantly changing shape from a cockroach into a much flatter cockroach. Delightful.

Even worse, the compressed cockroaches are still disarmingly fast. Even though their legs are splayed and their bodies are squished, they can still scuttle at 60 centimeters per second. “Scale that up to human size, and it’s like 70 miles per hour,” says Full. “They can run at high speed inside your walls and ceilings.” Hallelujah.

This ability seems doubly extraordinary because cockroaches, like all insects, have rigid exoskeletons. Soft-bodied animals like worms or octopuses can intuitively squeeze through tight spaces—just watch this octopus go—but it’s less obvious how a roach does it. “It’s not just crunchy, rigid parts,” explains Full. The exoskeleton consists of hard plates connected by soft, flexible membranes that act as hinges. Even the solid parts are variable, with some sections being 10 times less stiff than others. The result is a creature that can change shape without sacrificing its infamous indestructibility. Joy untold.