With so many current/former greys, it's a little hard to answer. But basically, they've all learned how to sit on command, albeit some more promptly than others. An obvious bribe does tend to induce a faster response. Some will even offer a sit in the hope of getting a treat. Poppy is the funniest--she'll follow me around the house, and toss in a sit whenever she thinks it might work. The other funny thing is to see one offer a sit and get noticed (whether or not the treat has been delivered) and then watch others rush up to sit as well.