Ulaidian
Songster
I suppose the problem is if your animal is catching and eating the rats, especially if they have been poisoned. When we have used the dogs, the chase instinct takes over, and they just chase everything, kill it, go onto the next one etc. Ferrets are brilliant at it as well, and make great pets 
Of course, we don't use any poisons at all, preferring traps and control via predators.

Of course, we don't use any poisons at all, preferring traps and control via predators.