The general rule for insects is that they should not be wider (from side to side, not head to butt) than the space between the chameleons eyes. Yes, they need to be gutloaded. You should still gutload like you would for a larger chameleon, so you need a wet gutload made from fruits and veggies, and a quality dry gutload like cricket crack, dinofuel, or bug burger. I, personally supplement pygmies like I do for montane chameleons. I use plain calcium withoutd3 about twice a week (depends on how often they are being fed though,) and a multivitamin once every 4-6 weeks. I will also supplement with a calcium with low amounts of D3 (like minerall) once or twice a month.