It depends how much your kitten weighs. The Litter-Robot senses the weight of your cat to know when it enters and exits, which triggers the countdown timer and cleaning cycle. Kittens and small cats that weigh less than 2.2 kilograms may not be heavy enough for the sensor to detect. Until they weigh enough, we recommend using your Litter-Robot in “semi-automatic” mode to keep your cat safe and relieve you from litter box scooping. For “semi-automatic” mode, leave the Litter-Robot switched off or unplugged. When you see your cat has used it, wait about 7 minutes for the waste to clump, then turn it on/plug it in. The Litter-Robot will automatically perform a cleaning cycle (takes about 2 ½ minutes), then turn it off/unplug it again. Continue this supervised, semi-automatic mode until your kittens have gained sufficient weight to activate the cat sensor.