(Taking dogs as an example here)

Pet cages are usually made of metal and used to keep dogs inside, preventing them from entering and causing damage, while also providing protection from getting sick from running around and coming into contact with dirty things. Perhaps you think keeping a dog in a pet cage is inhumane and cruel to dogs, but in fact, dogs view cages differently from us. Dogs treat their pet cages as their own little home, their own private space, and they also retain the lifestyle habits of their ancestors - wolves, who love to live in caves.

Dogs feel secure and not anxious in their own cage because it is their own private space. It may take a few days or weeks for it to voluntarily like its cage. With a pet cage that your dog loves, you won't have to worry about not being able to find it, and you can fully enjoy the happy time with your pet.