Lepidoptera: Limacodidae
Limacodidae sp
The response of the Cup Moth larva when disturbed or threatened is to suddenly shoot out stinging spines and yell "Take that you cad!"
I've never actually heard that last bit, myself, being on the deaf side, but I can confirm that the spines shoot out.
Vik's Wildlife Handling Tip Number 37
Avoid disturbing Cup Moth caterpillars, especially with any sensitive body part as the sting can be quite painful and irritating. Get a small child to do it.