Dog ate my homework!

We have a wonderful new dog, Milo. We adopted him last April. He has been great. Came potty trained and only has a few issues :) He tends to find things once in awhile around the house to grab and chew. It hasn't been bad he mostly chews and destroys his own toys. If you followed our last blog http://www.zorenaflattravelers.blogspot.com/ I have written about it once in awhile. I had a bright idea. When I saw the dog take something I would say, drop it do you want a treat. It worked great!! He dropped it instantly and I gave him a treat. I didn't figure out in time that I was rewarding his bad behavior instead of rewarding good behavior. The last week has been really bad as far as his taking anything he can reach and running waiting for us to tell him to drop it and wait for his treat :) Pens, pencils, paper, underwear, socks, towels, anything left in his reach has been chewed. Older son who is in college is taking a full load this semester to become a police officer brought home a take home test that is due Monday. He was sitting on his bedroon floor doing the test and who walks in and grabs it from him! The chase starts... Milo get back here, mom he has my test, grab him, Milo get back here. We finally resort to drop it do you want a treat. It works and older son tries to explain to Milo that in college the dog ate my homework line just wouldn't cut it even if it is true. He can still turn it in , but it does have teeth marks all over it!