I was feeding him some hair algae and I’m wondering what he’s doing? Normally I’ve seen them extend their necks but never puff up like this. I notice they like to bury themselves and when inactive, bothered, hiding, etc. they will curl up into a little ball and pull their heads in. It’s kinda cute but what’s going here? He was eating and half of him got puffy and changed texture? I notice they can make any part of their body completely smooth/sticky at least what I’ve noticed. What’s the reason for this?