The Proper Way to Knock

Oak goes to daycare alot( a couple of hours every day) and he has learnt a bad habit from the other dogs. When they want into the house, they jump up on the door. So now, he does this at home too. I am trying to break him of this habit before summer and he starts ripping apart screens instead! Before I let him in, I make him sit. The hope is he doesn't figure he is ordering me to let him in by jumping on the door. He does what I tell him too, then he gets in the house. I'm not sure this plan is working too well, so I went on the internet for suggestions. I found this website when googling "dog jumping on door" http://hubpages.com/hub/Unwanted_Dog_Jumping_Behavior There seems to be alot of good ideas on it. We are going to start trying the "Off" command and maybe get doublesided tape. I'm just afraid it will be too hard to remove when the time comes.