Abi hand fed one, but didn't brave the big boys, that looked a bit like they could give you a bit of a nip.
Having kept reptiles as pets before, I've been bitten and it was always associated with food. If they are squabbling and arguing, bananas are a prize and that might make them extra grabby. They could just lunge without looking too carefully at where their mouths are heading.
Most fruit and veg eating ones have teeth that are small, but needle-like and they chew by mashing their food against the roof of their mouths. It is a crushing bite and surprisingly strong, so its not great if they get hold of your finger by mistake.