It's just a hoop suspended below the feeder on strings, and the hoop is 'netted' with some old window screening. Nobody's gotten tangled in it in over 3 years.
I've got a picture of it somewhere . . .
The squirrels do get into the net, since it's near a tree but mostly the birds clean it out pretty well. I don't have any chipmunks here. I always will have squirrels because my house is surrounded by oak trees.
