The phrase "den instinct" refers to the natural tendency or behavior of certain animals to find or create a safe and secure hiding place, such as a den, where they can rest, protect themselves, or raise their young. Full definition
If your dog is introduced to crate training properly, the same natural den instinct will be triggered in the back of your dog's mind. (blog.pawedin.com)
«Beds with high bolsters simulate a pet's denning instinct for an added feeling of security and calmness.» (petbusiness.com)
Your pet dog retains this same denning instinct. (dogmanners.com)