Loki the Horrible

Loki just has been getting more and more aggressive. I invited the neighbors over to have some of the giant batch of veggie/ham soup that I made. I let the lady hold him and he was fine. Then as they were leaving, I set him down and he sunk his teeth into the top of my foot and drew blood. I think it must be over-stimulation with other people. He doesn't generally bite me otherwise. After biting me, he went and abused Chaos. Poor little guy...he's just too old for that. I'm not sure what to do about this.