In a bizarre twist, the stem cells around the injury site may actually form into a new tail, leaving a worm with two tails and no head. Lacking a mouth or brain, it can survive for a short time by ...

In New Zealand, they’re 2 to 5 centimeters (0.7 to 2 inches) long but can be longer elsewhere. The creatures are known as velvet worms because they’re soft to touch, but they’re also ...