They do seem to go through a crazy "get in my belly" stage where handling can be a little dicey. My older female grew out of it by her second year, still waiting on the younger male. Their food response is nothing short of insane so you always need to watch your butt on feeding days. Mine aren't in the least bit defensive and handle very easily. If you pay attention to their body language, you shouldn't lose blood. They almost always nose prod a couple times before chomping so if I get poked I simply direct their head elsewhere. They also seem to have a trigger spot dorsally, just behind the head, where if you apply a bit of pressure they shoot around and try to grab you. Maybe it's an adaptation for picking off prey that treads too close while they're basking with just their heads above ground? With frequent sessions I don't doubt they would "outgrow" these habits but I truly enjoy our interactions as they stand so I keep handling interactions to a minimum.