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It's best to start this trick when your ferret is lying down on the ground, rather than trying to press it down with your hands. So, wait for an opportune moment when your ferret is in a prone position, and place a treat about 8 inches (20 cm) in front of the animal's face. If the ferret hunches its back and scoots its rear end forward to reach the treat, keep moving the treat backward away from the ferret until it stretches itself out flat to reach the treat. As soon as the ferret lays down to get the treat, give it the verbal command: "lay down!" and slide the treat forward so the ferret can easily snap it up. Speak the command and move the treat simultaneously, so the animal comes to associate laying down with the words “lay down” and a treat. Don't try to put the treat directly into the ferret's mouth, or it could accidentally bite the tips of your fingers. Your ferret will only learn through repetition, so don't stop the training session after your ferret lies down once. Wait for it to recline a second time, then repeat the process: place a treat in front of the animal, say, “lay down,” and give the ferret the treat. With enough repetitions over a period of days or weeks, the ferret will learn to lay down on command. If you try to keep training the ferret for much longer than 20 minutes, you'll exhaust its patience and it will stop listening. Tell your ferret “lay down.” Hold a treat about 7 inches (18 cm) in the air and move the treat behind the animal's head. The ferret should roll over onto its back so it can keep an eye on the treat. As soon as it rolls, give the animal the treat and say “roll over!” Practice this 8-10 times in a row, always giving the ferret the treat once it's on its back. This should make the ferret roll completely over. Only move on to this step once your ferret is used to rolling on its back and hearing the “roll over” command. Continue to say “roll over” as you move the treat around the ferret's head, but don't give the animal the treat until it's rolled completely over and is again lying on its stomach. Remember to give your ferret verbal praise when it completes a roll-over. Say “good job!” in an encouraging tone of voice. In a single 20–30 minute training session, try to have your ferret roll completely over at least half a dozen times. It may take some prompting (or multiple treats per attempt) since this is a more complex trick than sitting or lying down. But, with time and repetition, your ferret will learn to roll on command. Once it's learned to roll on command, try pairing this with a couple of other tricks. For example, ask the ferret to sit, lie down, and then roll over.

Summary:
Place a treat on the ground in front of your prostrate ferret. Say “lay down” and give the treat to the ferret once it's prone. Repeat the command process 5-6 times in a 20-minute period. Circle a treat around the ferret's mouth to teach it to roll over. Move the treat in a full circle above your ferret's head. Practice these steps until your ferret regularly rolls over on command.