My guess, based on observation, would be odor. The first thing the Wheezyriders do when they get outside, by their own volition or by my good graces, is to SNIFF EVERYTHING. They run right to the nearest piece of outdoor furniture and sniff the holy crap out of it. As as far as my poorly functioning human nose can tell, it may very well smell like holy crap.
My mom gave me some potted herbs and a strawberry plant, all of which I am passively killing with neglect. So yesterday, I moved all the pots to an area just outside the back door hoping, maaaaaybe I’d be more likely to remember to water them if I actually saw them dying in front of me. But as soon as I opened the door, and with the stealth (and apparently the heft) of a jungle cat, Bill slipped out behind me and made with the sniffin’.
Perhaps if they were kittens, they’d be more interested in All The Moving Things instead of the inactive scents. We’ve got wind up here in the hills and everything’s moving all the time. There are leaves blowing around and the neighbor’s recycling comes to visit not to mention the bugs and the rabbit and the neighborhood pets. No chase? No? Sniff sniff? Ugh, boring!
Oh but when it comes time to go back inside, all is not well with the world. Bill harnesses his chi and becomes the heaviest most unmovable cat in the world. He hisses and cries like I’m abusing him when I pick him up and bring him back inside. It’s all very melodramatic.
Then Captain sits at the doors and cries “UNFAIR! How come I didn’t get to go outside today?” Because you have no real fur, little buddy. Or claws. And because you’re much much faster than your brother.