hour for every month of age. Owners of young dogs will have to continue to take the puppy outside frequently. The crate is the only space in the entire house that truly belongs to the dog, and if used appropriately, will become a safe haven for years to come. Locking the dog in a crate and letting it whine, bark and attempt to escape is common but such attempts to introduce crate training may cause a negative association with crating. The dog should become slowly accustomed to the crate. This can involve making a crate an inviting place by placing small familiar toys inside, moving the pet bed into crate, leaving unwashed items of the owner's clothing inside, rewarding pets for entering the crate and remaining inside, incorporating the crate as part of play, feeding the pet in the crate, allowing the pet to explore and use the crate until it is no longer intimidating, and eventually building to the pet sleeping in the crate overnight. Part of proper crate or cage training requires that the pet owner observe calm and relaxed behavior around the crate. The pet will attribute any emotional responses such as raised voices or other nervous behaviors to the foreign object in their normal environment. It is important for the owner not to create any negative associations with the cage in order for the pet to accept the crate in a calm manner. Adverse effects Without proper conditioning, dogs may vocalize their distress and make efforts to escape the crates. Crating suppresses the dog's behavior, removes the dog's freedom of movement and is a negative punishment (removal of reward) under operant conditioning. Dogs who do not react well to negative punishment may find crating highly stressful. Long term or excessive crate confinement "may lead to emotional and behavioral deterioration over time." To the extent that crating reduces the amount of exposure to different environmental and social situations, it can make dogs more reactive (fearful or aggressive) or intolerant of novel situations. Crating "may significantly exacerbate the distress and emotional reactivity associated with separation distress". Behavioral problems that compels owners to crate train in the first place, may be exacerbated by the negative effects of crating. A dog may form a strong attachment to the crate eventually, feeling comfort and safety, after the initial feeling of distress and vulnerability. One dog behaviorist has compared this behavioral effect