That's very true. That's also why I confessed to hating mice. Mice do eat each other and their offspring a lot more often than rats will. However, that doesn't mean that mice are difficult to breed.
My dad and I had a rather extensive collection of snakes while I was growing up, and we had an extensive rodent breeding colony to support the collection. We maintained about 12 breeding female rats, and 25 cages of mice that had 2 or 3 females to 1 male. We did not use professional breeder racks; we had the whole operation housed in the basement, which was quite large... but we went cheap on materials because our collection was a HOBBY, not a BUSINESS.
By "going cheap on materials" I do not mean we used inferior materials, just not pretty materials for housing. For mice, we took very heavy duty 5-gallon buckets, drilled a hole in the side for the water bottle to come through, and enough smaller holes to mount the bracket to hold the water bottle, and gravity feed chute of our own invention. Around the water spigot we also attached hardware cloth (wire mesh) to prevent the mice from chewing their way out (the round sides of the bucket helped with this too). The whole thing was covered with a sheet of hardware cloth, shaped to fit around the top of the bucket without posing too much of a snag hazard. This was held on with weights.
With this system, we only ever lost one mouse litter to a female eating it in about 8 years of breeding mice. We never lost a litter of rats this way. We housed our rats in lab-style rat cages.
In fact, we had to tailor this system a few times, because we actually over-produced mice and exceeded our own needs.
I wouldn't guess that heat would cause enough stress to prevent mice from breeding - but how hot are your thinking they got? More than likely, you had one freaked out female. Female mice are more likely to eat their first litter than any subsequent litters. Also, first-time mothers may feel that their safety and the safety of the litter is threatened by the presence of the male. This is even more true if the male that is present is not the male that sired the litter. That will even cause rats to eat a litter! (This behavior has been studied extensively in mice and in rats in both wild and domesticated situations)
So, don't just give up on breeding mice, if that is what your reptiles are eating. Mice stink awfully bad, but breeding your own is a helluva lot better than paying $1.30 per mouse (that's what I have to pay anyway). I personally do not breed any rodents right now just because my husband and I don't yet have a place to keep them that would not be in the house - and they stink!
Good luck!
~Rebecca
-----
0.1 Dumeril's Boa '04 (Courtney)
1.2 Ball Pythons
[1.0 '05 Orange Hypo (Specter)]
[0.1 '05 Het Orange Hypo (Sylvia)]
[0.1 '03 Normal (Sue)]
0.2 American Pit Bull Terriers (40lb darling lap dogs:Brandy&Mara)
gotta love 'em.