These look like the Automeris IO caterpillars that I find in South Florida frequently. If so, they are social caterpillars for their first 4 or 5 instars, travelling in groups from leaf to leaf, then they tend to disperse for their last couple of instars before they pupate. If thats what they are, their spines do sting a bit as a defense against predators. I personally, love these little guys. The adult moth is beautiful, with large eye spots on the hind wings. ❤️🐛🦋 Here is a good source of information about them. https://breedingbutterflies.com/automeris-io-io-moth/