Rats mice infestation in the attic will lead to disease. An experienced exterminator will recommend a Rodent clean up
Get Rid of Rats and Mice
Rats and mice breed fast. A mouse can have several young when she’s two months old. Then, two months later, her young will breed. In the meantime, the mother will produce another litter. So you must keep working to get rid of them. Certainly you can get rid of most of them.