Oldman47
ArboristSite Guru
Read the labels on rat poison like D-con. It is illegal to use it outdoors.This looks very good. The 3" PVC would be about right for squirrels. All the bottom T lengths (vertical and horizontal would only have to be a foot long and you could fasten it to the base of Mr. Squirrel's favorite tree. I believe it takes awhile for most rat poisons to do their work, so the squirrels will likely die elsewhere.
Worth a try in my book. The squirrels are completely overpopulated in my yard and are now tearing up my pin oak tree like gangbusters. I've carried out over two trash cans packed with green twigs and leaves that the squirrels have ripped off the tree.
Don't get me wrong, I think it is a great idea but it is a prohibited use. Be aware of that before you do it.