A dog crate (sometimes dog cage) is a metal, wire, plastic, or fabric enclosure with a door in which a dog may be kept for security or transportation. Dog crates are designed to replicate a dog's natural den and as such can provide them with a place of refuge at home or when traveling to new surroundings. Other common reasons for using a dog crate are for toilet training a new puppy, transporting a dog, limiting access while the dog learns rules, ensuring the dog's safety, confining a dog in locations where dogs cannot safely or legally roam freely, or giving a dog a place to go when visitors come to the house. Crate training accustoms the dog to the crate so that they can rest in it without stress. Using a crate for a dog is similar to having a playpen for a toddler or a crib for a baby, and allows the owner to take their eyes off their pet. However, misuse (such as prolonged locking) can cause the dog psychological harm. Types of dog crates There are many types of dog crates, and variations within the types. Factors to consider when choosing an appropriate crate include cost, durability, portability, safety, and style. Solid plastic crates are usually more suitable than other types for secure travel, such as in an airplane. They might also be safer in a car accident than wire crates. Disadvantages are that they take up a lot of space and do not fold for storage. Travel Crates are designed specifically for use in vehicles for pet vehicle transportation. These crates are not intended for use on airplanes or for carrying pets outside of vehicles. They also do not make good housebreaking crates. Aluminum crates can be either fixed or folding. A few of their advantages are: light weight, very strong when constructed with appropriate bracing, will not rust, excellent airflow and vision for the dogs. Aluminum crates are suitable for use at veterinary hospitals, car travel, as a permanent "den" for your dog inside the home and in breeding kennel environments. Some aluminum crates have solid walls and some have bars. The crates with bars may be more suitable for dogs who need to see out to feel comfortable. Other dogs may prefer the den like feel of the solid wall variety to feel secure. Wire crates usually can be folded for storage or