A "safe den" refers to a place or environment where someone feels completely secure and protected. It is a comfortable and peaceful space where they can rest, relax, and feel safe from any dangers or worries around them. Full definition
For dogs, consider crate training from the start — many pups see their crate as a safe den for sleep. (health.com)
After its carnivorous feast, it will then retreat back to its safe den to wait for spring, and of course, resume its vegetarian lifestyle. (petsmagazine.com.sg)
Puppies have a natural tendency to stay in their safe den, while adult dogs typically need a little coaxing before they start seeing the dog crate as their den. (web-rover.com)