One of my chipmunks who is now departed lost her tail, we had gone on holiday leaving a family member looking after the chipmunks, when we got home we noticed Poppy our female had lost her tail, there was no blood, I searched the aviary for signs of the missing tail but could find nothing, we do have a wheel in the aviary that the chipmunks love to run on, we always wondered if whilst running on the wheel her tail got trapped/pulled off, it never impaired her one bit.