Don't know when your pup needs to go out to do his business; that scratching on the door isn't a clue?.

If you don't have a dog door , here's a handy pet chime. You just teach Fido to press the portable wireless electronic doorbell in the shape of a paw. (They make that sound so easy; they don't know my dogs.)

They say you can use it with both dogs and cats. The chime gives you two choices of tones - either a dog bark or the traditional ding-dong chime. I wouldn't recommend the dog bark for your kitty cat. The remote control works up to 100 ft. away from the chime. Paws are weather-resistant and battery operated.

$29.95 at Cool Pet Stuff.