Fascinating the way cats retain so much hunting instinct despite domestication, though I realize Lego is a special instance, genetically. Since my wife's cat has so much hunting experience, she watches the boy litter mates attempt to hunt with a condescending air. They skitter and poke at an early fall mouse who's wandered into the warm house. She waits until the boys get bored and wander away. Then she goes into an ambush, waiting any amount of time, and when the mouse thinks it's safe and moves toward safety, bam. She has it parked next to our slippers in the morning. We keep her inside here, for vehicle traffic and a problem with FIV with an earlier much loved cat, so she lines up toy mice at our bedside, and we praise her lavishly. I think often the females are more active hunters, because they have to feed their litters. However the most active hunting cat I knew was a rather medium sized male that had been declawed (not buy any of us, he was a rescue). But that little guy bought down adult rabbits and squirrels along with the usual smaller animals. He also established leadership with a formidable much loved dog and various dogs boarded at the house. He also socialized with neighbors, and people knew him a wide radius around the neighborhood. He'd visit their parties and sometimes do overnights. And he was extremely easygoing about sleeping with people, on your shoulder or against your leg. This was my sister's cat, and most unusual. There's a certain amount of truth in the idea that cats domesticated people for their purposes, as much as the other way around.