Well, it's best done as seldom as possible, because their skin is so delicate and they are so sensitive to toxins, which are absorbed through their mucus-membrane skin. Things you might have on your hands can be bad for them--hand lotion, hot chicken wings, whatever you touch. If you handle them, wash your hands first and make sure there's no soap etc. residue left. Your hands should be wet, also. Then wash them afterwards as well, that's a good idea. Also, it's not like they're mammals, that like to be cuddled. They don't really care about that at all. They run to you because you bring them food.