Rats in the Attic Problem

[Eric Wang]

I have what is know to be "Roof Rats" in the attic. Apparently, they are finding there way in through the cracks of the old wood roof shingle. I have couple of option:

A) Hire a pest control company and takecare of the problem, they would
check and seal all opening on roof, set traps and clean out attic to get rid of rodent scent and droppings and decontaminate if necessary. Cost $300-500

B) Do it myself, which I don't really want too but would be the cheapest solution. I'm just concern I might not be able to locate all weakpoints.
Also, can I spray the Bioshield decontaminant myself to get rid of the droppings? For health reason, the droppings needs to removed completely?

C) My roof needs to be replace soon, according to the roof inspector, roof will last another 5 years. This will cost me around 15K for new composite roof.

Do you guys have a better solution in solving this problem?