They can be easily spooked. Cleo is quite a nervy hamster & doesn't seem to like "outsiders", i.e. People she doesn't know, in her cage. Also she hates having her head touched or anywhere hear her head & when a family member went to pet her they went straight for the head - they're a cat person so seemed natural to them. She was quite off for a few days & didn't want to come out or have a lot to do with me.
If Nico got a bit agitated by his "experience" then give him a few days of minimal contact - like when you first bring them home & build it up from there. I'm sure he'll be back to himself before you know it. He just needs to work out that nothing bad is going to happen when he comes out
