Q: One of my first grade students found a pretty caterpillar. It was about an inch and a half long, mostly white with yellow accents. It was very skinny and had what appeared to be very large antennae that were white tipped with yellow.

There were white hairs growing along the sides and 4 yellow balls on top of it.

A: It’s a tussock moth, specifically a white-marked tussock moth….Orgyia leucostigma

see
http://entnemdept.ufl.edu/foltz/eny3541/Tussock/Orgyia.htm