There is no wait, it only locks if it finds some prey. Of course there are occasional false positives. But those are very rare (haven&#x27;t compiled the exact statistics for that though).<p>The chase thing has happened, but since the door to get in is very small other cats don&#x27;t tend to follow.<p>Since it&#x27;s really cold here in the winter I also chose to design it so that the default mode is for the door to be open. So if there&#x27;s a power outage it will always be open.<p>Regarding the weight thing. I don&#x27;t think it&#x27;s feasible unless your cat always brings in rabbits or something, the weight difference is so tiny. Too many variables come into play as well, temperature differences being one, a wet cat compared to a dry one and so on. Might work, might not :)