good terriers never back down that is there job to stay until the end, so never pen them together especily them little black ones its an accident waiting to happen. my terriers get on very well hunt together and sit in the same box in the van, but there is no way they would be left in the same kennel, because its gona happen some day usually when they are comeing into heat, i have also heard of older bitchs killing pups as the pup will want to play all the time and the bitch will lose the head eventualy, all depends on how hardy the dogs are and how well you can trust them i would not take the