You're probably going to have to try trust training or forced socialization. You may need to put something in there that smells like you (sleep with a towel or carry scrapes of fabric around for a while) to get them used to your smell. If you can pick them up and hold them, doing so for about twenty minutes a day will help. If you can't, find a pouch or small pack or even a towel and put them in that so they have something to hide in, but keep them close to you to see if they'll eventually get curious and come out. Then let them climb on you and learn you're not dangerous.
Be persistent and do it daily.
It does help.
Be persistent and do it daily.
It does help.
