keeping him busy

by Kathy
(New York)

Help! We have a Jack Russell that is three years old. We need some ideas to help keep him busy, especially when he's home, alone.

We do not have a fenced-in yard but provide a long run (50 feet or more) outdoors. We play ball with him twice a day until he poops out and take him on a two mile walk at least four times a week, weather permitting.
Indoors, he gets bored. We have given him all types of interactive toys and stuffed animals, but he destroys them in under two minutes. Worse yet, he EATS the pieces! This worries us, so we haven't given him anything except his ball, which he needs us to throw.

Is there ANYTHING that will give a Jack something to do, that he CAN't destroy and eat??