Only the life cycle of the Roof Rat (rattus rattus) is discussed on this page since this is the only rat that is common here in central Dubai.
Roof Rats are born in a nest, in a litter of 6-8 young. The nest is often in a secure place with nesting debris such as in an attic in the insulation. They are born tiny and hairless (pinkies), with eyes sealed shut. After two weeks of nursing, their eyes open, and within 4 weeks, they are weaned. After three months of life, they are independent and on their own, although they typically use the same habitat as their birthplace (i.e. they live in the same home or attic).
Here we can see a photo of a juvenile rat and a mature adult rat. Older ones sometimes tend to brown a bit, although most of the rats we catch are gray. A lot of the rats that we catch are small rats. This is because they breed in such high numbers, and there are so many young ones. When we’re trapping rats in an attic, we’ll often get a big one or two, and a number of small ones. This is not the rule, but it does happen from time to time, indicating a possible family of rats.
Rats don’t live particularly long in the wild. Like all rodents, they rely upon breeding in high numbers and eating a lot and growing quickly. In this respect, they are somewhat like insects, and thus can sometimes swell to large numbers given the right conditions. In normal circumstances, disease and predators keep their numbers in check. Rarely do rats live for more than a year in the wild. During that year, however, they can create a lot of new rats and a lot of damage. Just one adult female can create more than 40 new rats in a year. In their lifetime, rats tend to stick to familiar territory. They are not explorers. They find an area that suits their needs, with shelter and food (human homes and attics quite often fit the bill) and rarely venture more than a few hundred feet from that area. They rarely die naturally, but when they do, it’s often in safe place like your attic, and you’ll notice the smell. Most will be killed by predators or OrlandoRats, Inc. However, they’ll leave their damage and their offspring behind.