Odd title, isn't it? People ask this all the time!
Had someone the other day who got a second chinchilla from here, and wanted to intro it to their first. Of course, if you've read this blog with any regularity, you know that there's no way to know if two chins will get along without trying it, and no possible way to guarantee that any two chins will get along. So, anytime you try to introduce two chins, you have the very real possibility that the may not get along, and they may even injure each other.
Even if kept in separate cages, there's several homes I can think of, where they let the chinchillas out for playtime, separately, mind you, but the cages are both in the same room, so the chin who is running around can go up to the chin that's still in the cage and potentially go after the chin. In the situation that made me write this blog post, the chin having playtime went up to the cage and bit off a finger of the chin that was in the cage. You read that right.
Before you have a heart attack... It happens ALL the time. I don't count fingers and toes of chins that leave here, but I'd be willing to bet that at least 1/5 or more are missing some. Mainly because siblings will chew on each other, or another chin will chew on a finger when it's pressed up against the wire that separates cages... but fingers and toes (and ears) are the most common casualties of chins getting chewed on. Not the end of the world, the chins don't even notice they're missing anything once it heals (and it usually heals really quickly).
But one thing I should mention, since people ask, all the time -- no, the finger / toe will not grow back.
Chins aren't lizards / geckos, to start with. So when a body part comes off, it comes off permanently. Did you know, there's actually very few species of lizard where a body part does grow back? Even in the ones where the body part does grow back, it's typically a tail, and the new tail never looks quite the same as how the old one was. But for most lizards / geckos, if they lose a body part... it's just like us losing a body part. It's gone, not coming back.
Just to let you know...