Hi, Nancy:

It's been my experience that poles are easier to varmint-proof. It's difficult to stop racoons and snakes from getting to the houses when they're attached to trees. You could try hanging them but, of course, access to check the nests can be more difficult. I had them up on poles and was able to attached snake barriers and/or racoon "skirts" to them fairly easily. Good luck!

Regards, Joanne

Joanne Powell
Airway Heights (Spokane) WA
mailto: jopowell2 at juno.com