I'm loving "Dispatches from Tanzania!" I had no idea that some rats have pouches. I'm guessing that the pouches are a similar to those of kangaroos. Does this species of rats use their pouches for their young as kangaroos do? ~Art For Life Member
No, they don't; but this actually is a very common misunderstanding. The Pouches are in their mouth, not on their bellies. When people hear of an animal with a pouch, most automatically think of belly pouches that Marsupials would have. Kangaroos, Koalas, even the opossums (of North America) are Marsupials. They birth very under-developed young that complete their natal development in the mother's belly pouch.
Since, some people assume rats have belly pouches, they may confuse them with wombats. Wombats and Pouched rats (that rhymes!) are ecologically similar: both live under ground, dig extensive burrows, live in very similar habitats and mostly active at nigh; but the pouched rat gets its name from its mouth or cheek patches.
Cricetomys have pouches like chipmunks: two pockets indie of their jaw, one on each side. They use them for storing food when they are out on foraging runs. When they return to their burrows, they empty the pouches and store the food (usually grains, seeds, and nuts) for later consumption.
I've seen my rats in the lab stuff their faces with rodent pellets and dump them in the corners where they sleep. Here in Tanzania, I've captured a subject who gobbled up all of the corn from the cob (bait) and had it sitting in her pouch. She let me do all of my measurements and handling and hardly spilled a kernel.