 There are concerns as to whether breeding hairless and tailless rats is ethical . The tail is vital for rats ' balance and for adjusting body temperature . <unk> rats have greater risk of heat exhaustion , poor bowel and bladder control , falling from heights , and can be at risk for life @-@ threatening deformities in the pelvic region like hind leg paralysis and megacolon . Similarly , hairless rats are less protected from scratches and the cold without their coat . Groups such as the NFRS prohibit the showing of these varieties at their events and forbid advertisement through affiliated services . 
