Crabs, birds, and manta rays regularly try to crush sea horses for dinner, but a sea horse has some unusual protective armor. Its tail can be compressed to half its normal size without lasting damage, researchers at the University of California, San Diego, recently found. The tail's resilience comes from its structure: approximately 36 square segments, each made of four bony plates. The plates connect to the spinal column's vertebrae with collagen and can glide past one another, keeping the spine safe. Ultimately, the researchers would like to build a robotic arm out of 3-D–printed plates that mimic the seahorse's flexible and tough tail and use it for underwater excursions or to detonate bombs.