Mice smell horrendous!! Rats are not bad; I have roughly 30 of them at any given time, living in tanks in my laundry room. I use pine shavings as bedding and clean them every 6 days and it is fine; the more crowded the cages; the more cleaning is needed. But you should do it; I am feeding my 4 snakes nicely and I have not bought a rat in months!!