I sometimes have to feed live geckos..... I HATE it in a way...They squeek. But it doesn't bother me in another way... I wouldn't say I am desensitized. I just have seperate places in my head and heart for feeders and for pets (I have kept rodents etc as pets and love them and would NEVER feed them, but I have fed live (or purchased live and killed) over the years on many occasion)
I just seperate them and move on. But thats just me. *shrugs*