I have 5 female rats (4 adults, 1 almost-adult). I also have 3 dogs and in their bag of dog food we got a sample in separate packaging of Pedigree Dentastix. Our dogs refuse to chew on them, so I was wondering if this was all right for the rats to chew/eat? (My girls have quickly learned that if I'm giving it to them, it must be good, so they've lost their cautiousness they had when they were babies.)