A few instances of first-generation anticoagulant resistance have been reported in roof rats; although not common, it may be underestimated because so few resistance studies have been conducted on this species. Body is smaller and sleeker than the Norway rat’s. Rat treatment involves both non-chemical and chemical methods. Make sure that all doors, windows and screens fit tightly in their frames and repair those that do not. A mouse's tracks will be much shorter. In controlling roof rats with rodenticides, a sharp distinction must be made between control in and around buildings and control away from buildings such as in landfills and dumps, along drainage ditches and streams, in sewer water evaporation ponds, and in parks. At least in some parts of the United States and elsewhere in the world, the methods used to control rats have reduced Norway rat populations but have permitted roof rats to become more prominent, apparently because they are more difficult to control. Breeding seasons vary in different areas. Got a rat problem? Let rat removal experts get rid of your rat problems so you don’t have to! Many people want to know how to kill rats, but the reality is that killing the rats may not be the best solution to your rat infestation problem. Roof Rats are commonly called black rats and are smaller than Norway rats. These rodents have been known to consume tree bark, meat and grain.