Here's a WiPedia thingie on Catnip, where I learned that 1) It's NOT related to cannabis, 2 only half to two thirds of cats react to it, it's genetic, and a lot of Australian cats aren't affected, and 3) it's got nepetalactone in it which, when distilled, may be 10 time more effective in repelling mosquitoes than DEET. You're gonna need that up in the tree.