We have 2 leopard geckos that are about 6 months old. They were eating constantly in the beginning and now they are both refusing to eat crickets for about a month now. We are giving them mealworms but one of the geckos keeps grabbing them in his mouth and spitting them out without eating them. Essentially he is not eating and tonight I noticed he has bubbles looking bumps under his armpits. What does that mean and what can I do?