He is usually more interested in legitimate treats, but if he's really focused on something and you stick hot dog in his face to get his attention, he will irritably duck his head around that annoying chunk of MEAT obstructing his terribly important view of construction workers or crows or a bush he's walked past twice a day for the last week. (Construction workers, very interesting. And their fascinating vehicles. He's like a toddler.)
He is interested in toys at unpredictable intervals, for about 30 seconds at a time. (The bees usually last longer. He likes the bees a lot.) He's reliably interested in toys if something really exciting he's not supposed to mess with is happening (e.g. people coming to the door), which is nice because it means you can toss a toy away from the exciting but disallowed thing to distract him. Sometimes he'll even go grab his toy as a displacement activity all by himself.
It's hard to figure out how to reward him for things, since what he wants varies so much. We suspect that what he really likes is novelty, which is... difficult to supply at need.
He appears to have caught on that we do not want him messing with the chickens, and has not attempted to put his giant feet up on the card table their cage is sitting on in a few days. I brought a beanbag chair out of the closet to sit and watch them, and Galen has decided that the beanbag chair is the BEST THING EVER. It is better than being with people, even -- last night he stayed curled up on the beanbag well after chinders and I had gone to bed, which is very unusual behavior. Today he's been in and out, dividing his time between hanging with the people as usual and hanging with the chickens on the beanbag. This may not last, but I'm glad we've got something he enjoys for now. (I suspect the chickens may be part of why he likes it in there -- their peeping is very soothing, and the heat lamp in the brooder means that it's warmer in that room. Now that they're not a NEW THING WHAT IS IT ARGH TOO HIGH I CAN'T SEE, he doesn't seem bothered by them at all; he doesn't even react when they change the tone of their peeping to indicate alarm.)