How many breeders do I need?

[Lolo76]

Despite my dislike of the little creatures, I've decided to start breeding mice again... my trip to the pet store for 20 mice today convinced me of that! With a collection of 23 snakes, a handful of whom eat multiple mice weekly, how many breeding females do I need? I'd say that I average 15-20 live mice per week (I also feed frozen but order those in bulk), so would 3 or 4 females and 1 male mouse be enough?

Last time I bred I only had 1.2, since my snake collection was smaller... at first they were giving me small litters, but by the third round I was getting 10 at a time. Is that fairly normal? I'm planning to get the breeders at a different shop this time, where they have larger than average adults - always looking nice and healthy. Should I spread out introducing females, so they don't have litters on the same schedule? Final question! Will a 20gal glass tank be sufficient for this colony, and does glass hold the smell in better than a wire cage? TIA for any advice, and wish me luck...