Do Squirrels Chew on CQs?

I have had several calls asking do squirrels chew on CQs. Well, all I can say is we have well over 13,000 in the field over the past 3 years and I have had no complaints. In fact, in my neighborhood I have several installed on various homes that I use as my control tests to check periodically and I have not seen any damage in 3 years. Just the other day I saw a squirrel climb up on one, check it out, and leave it.
Generally squirrels chew on lead because its soft, and they have been known to chew on PVC, but we use a petroleum based plastic so this may be a deterent. But I  cannot say this definatively.