Eliza, when we lived on a mini-ranch (25 acres in Wyoming) I did let our cats go out at will. There was always a risk of eagles hunting them. We had a darling cairn terrier who just disappeared. One cat went missing for over a week, came home in the middle of the night. he was emaciated and weak, obviosly having been locked in somewhere. He left after we went to sleep. I assume he went to die alone. We found him again. We later found out he'd accidently been shut up in a neighbour's qounset hut with no way out until they happened to open it and saw him run out. So, yes, there are birds of prey and other dangers out of town, too.

Getting back to the original posting, see DRS FOSTER & SMITH Cat Training Aids.