A ball that only moves when someone throws it is no use to a dog on their own at four in the afternoon. This one moves by itself: it rolls, rotates and bounces off in a direction the dog did not predict, and because the movement is motion-activated it responds when they paw at it and settles down when they lose interest. For a dog with more energy than the day is giving them an outlet for, unpredictability is the whole point, and it is what a static toy can never provide.

The shell is E-TPU, a foamed plastic that gives a little under a bite instead of shattering the way hard plastic does, and it is rated IP54, which covers dust and splashes from any direction. That makes it fine on a wet lawn and fine to rinse under a tap. It charges over a cable rather than eating batteries, and comes in orange, blue, pink or red, which matters more than it sounds when a self-propelled ball has taken itself under the hedge.

• Rolls, rotates and bounces under its own power
• Motion-activated, responds to your dog's play
• Food-safe E-TPU shell
• IP54 rated for dust and splashes
• Rechargeable
• Four colours: orange, blue, pink and red

Two important limits. IP54 means splash-resistant, not submersible, so this is not a toy for the lake.

Who it's for: Active medium and large dogs who need something to do while you work, supervised at first until you know how they treat it.