When looking for signs that squirrels are in your roof, you need to be sure you can identify what those signs are, and what you can do about the issue. In general, you should be able to tell whether squirrels are in your roof by checking out the various small holes that they leave. Squirrels also have a particular way of marking out their territory, which can be seen by looking at the scat. Scat is the faeces of the squirrel. If you find litter, it is a sign that squirrels are nesting in your roof. Whether they are in the trees or just in the rafters, you should be able to tell if you have squirrels in your roof by examining the conditions and the scat.
Squirrels are mostly an issue for homeowners who have large mature trees overhanging or right next to the roof of their property. Squirrels live in the trees and will use a roof as another platform for their activities, possibly getting in through small gaps in the roofing and using the loft space for shelter and nesting. For help from Pest Control Harlow, visit a site like BPC, providers of Pest Control Harlow.
In general, you should check your roof at least once a year. Take a look at the attic and check for scat or any signs of nesting materials. If you can, try to watch for new nests as well. This could also help you in determining the frequency of the problem. If you find that the problem occurs infrequently, you can decide whether or not it would be worthwhile to pay an exterminator. If you can eliminate the conditions that attract squirrels to your roof, you can avoid problems for a long time.