Training a puppy to be comfortable in a crate is a popular way to provide safe confinement during house training. The majority of puppies will rapidly accept crate confinement when you make the introduction fun. Since it is important to associate favorable things with the area where your puppy is confined, it is a good idea to play with him there, or simply spend some time reading or watching television nearby as he relaxes with a favorite chew toy. If he is only in the area when you leave, it becomes a social isolation area that he eventually may resist entering.
A good time to start crate training is at dinner time. Feed your puppy his dinner, one piece at a time, by tossing pieces of kibble into the crate for him to chase and eat. This way, you can make a game out of training.
When you pick up his toys, store them in the crate so he will enter on his own to play. You may even want to occasionally hide a biscuit in the crate as a nice surprise.
You should not use the crate for periods that exceed the length of time the pet can actually control the urge to urinate or defecate. If you are gone for long periods each day, you will need to provide a larger confinement area. You may want to consider using an exercise pen or small room.
Provide an area large enough so that if your puppy has to eliminate when you are gone, he can do it in a space that is separate from his sleeping area. A 15- to 30-square foot area is adequate for most puppies. If he chooses a specific place to eliminate, cover it with paper to make clean up easier.