In 2001 I bought a single rosy boa, followed a bit later by 2.1 california kings. I got tired of going to the petstore to try to get the right size mice, and with the Rosy being a very picky feeder I especially hated buying mice that would go to waste. And I was spending $1.00 to $2.00 on the mice. Hubby wasn't keen on mice in the freezer, but I was keen on snakes, so live mice was the only purchase option. (gotta keep domestic bliss going right?). So when his kids were here at Christmas, we took a vote. Could they handle it if their new stepmum would raise mice to feed to snakes? Well the unanimous decision was that so long as some would be pets, particularly the 1.2 starter group that the 1.2 kids could name, then it would be fine. Thus my husband was sunk in his attempts to thwart my mouse breeding plans.
Well Soon I got fascinated by the genetics of the mice, and I got more and more, and then I had to justify all the mice, so I got more snakes. Now I have enough snakes to justify my mouse breeding colonies.
As far as the pros and the cons, they were listed well by another reply, but I'll just talk about what I've experienced.
To begin with the three or four week old mice that I purchased took forever for them to breed. But once they started they were right on schedule. Cannabalism was an issue, but not too bad. SMELL was a huge issue, since at that time we rented a house, and hubby didn't like to share his air with mice. So I kept them in a room with an outside door, and cleaned them two or even three times a week. It actually cost a bit to begin with, making lids for cat litter pans, buying plastic critter cages, water bottles, bedding, figuring out the best food.
Now, however, I have thriving mice colonies that do what they are supposed to do... create babies. Of course I still have fun with the genetics of the mice, and create all sorts of bizarre strains of mice. But I feed them when I clean them, they are in their own shed, I change their water, feed them, and change their bedding twice a week. It takes me about 2 1/2 hours to do all of that. (35 mouse cages, 2 gerbil cages, 3 rat cages). I spend about $300 per year on the mouse food and bedding, probably less, but that's the maximum. I sell extras to the petstore, and last year I made between $500 and $750 from sales of mice, not to mention a few nice trades of mice for snakes. The mice produce between six and twenty offspring per litter, and when it's feeding time for the snakes, I have rats for the pythons, adult mice for the adult colubrids,a nd every smaller size for the neonates and the juvie snakes. I figure that if I make a $250 profit off of the mice yearly, and don't pay a dime for the feeding of the snakes, and all I have to do is spend a couple of hours twice a week, it's not a bad scenario.
Mice do bite, they do stink, and they can eat their babies if things aren't perfect. But in general, I enjoy them. Rats are as fun, but I've only just got started on them. The Gerbils are even newer, and I should have my first gerbil litters at the beginning of February.
So anyway, if you have more than a few snakes, if you have the space to raise the mice, and the tolerance of the work and stink that goes into keeping them, then raising mice is a good plan. But if you don't really like the idea of having to raise the mice and care for them, and/or you have a small number of snakes, the better bet is to buy in bulk frozen and not worry about it. Again, it's all one of those things that ends up coming down to personal taste and preference. You won't really know if it is for you until/unless you give it a try.
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~Sasheena