Thigmotaxis is biology-speak for “squeezing into a hug”. It is seen in lots of animals from humans down to baby caterpillars and has lots of causes. Mice do thigmotaxis because it helps them stay close to walls and other solid objects which keeps them safe from predators and brooms. Fish do thigmotaxis because it helps them bunch up and look larger which discourages predators. And elephant seals do thigmotaxis because it helps them get through the stressful molting period.