Some dog and cat owners sometimes wonder why their animal needs to wear a pet license tag (also called a pet I.D.) all the time. This is especially true of the owners of strictly indoor cats, or of dogs restricted to secure, fenced-in backyard enclosures. The answer can be summed up in three words: safety, safety, and safety.
The fact is, with incentive enough (e.g., a squirrel on the run), most pets are smart and determined enough to thwart the most secure enclosure. A fence can be leapt over or dug under, or your careless teenager can leave the front door ajar—and then, before you know it, your pet is outside and in the wind.