To ensure the comfort and safety of your cat, we strongly advise against using the Litter-Robot in unsupervised, automatic mode for kittens or small cats weighing less than 5 pounds.  Due to their low weight, kittens and small cats will not activate the cat sensor.

You can, however, start the Litter-Robot cleaning cycle manually by turning the unit on when the litter bed needs to be cleaned and then turning the unit off again once the cycle has been completed.  You can continue this manual "supervised" mode until your kittens have gained sufficient weight to activate the cat sensor.  In this way, you still benefit from not having to scoop the litter box by hand.

Please read 'Is Litter-Robot Right for You and Your Cat?'