Drifter has many characteristics of a baby horse. I rather suspected he would be this way, after observing his interactions with his owner when I visited with them last fall. He's a horse who's friendly and cooperative - but he's cooperative when he feels like it and not so much when he doesn't want to be. That is, he feels he should get to call the shots - not because he's a particularly dominant horse or bad, just because that's what "baby" horses do and it's the way he expects things to be because of how he's been handled and "trained".
Two examples from this morning. I couldn't make it to the barn last night to pick feet and wanted to pick them this morning - our mud is dreadful and I'd like to keep thrush at bay. Drifter's been pretty good about foot-picking in the stall in the evenings. But this morning I wanted to pick his feet when he was interested in going out and watching the other horses, and he didn't feel like being as cooperative. He took one front foot away from me and slammed it down - I just was persistent and picked it up again and we got the job done. With one hind he tried to cow kick - he did get a swat for that as it's completely unacceptable but just swatting him when he does it wrong isn't enough to train him to do it correctly. I went right back to asking, rewarding small increments of foot lifting and we got the job done without him trying to kick me again.
After I turned him out in his paddock, I worked more with him on foot lifting. This didn't work when he was loose - his response was to walk off to avoid doing what I wanted. So I tied him to a post in the paddock - this involved taking him away from his hay which as a "baby" horse he didn't appreciate. We worked more on foot-lifting. With the "bad" hind, he tried to cow kick again and I didn't need to swat him - he acted like I had since he already knew this wasn't what he was supposed to do. I went back to rewarding foot lifts of that foot. We're going to do a lot more of this this evening - I'm going to do some clicker work rewarding him lifting his feet and holding them for picking for longer and longer intervals - he's already got the idea of clicker from our backing one step for a hand gesture or a touch, and I think he'll find clicker highly motivating. Initially, for safety's sake, I'll probably work with his hinds while he has a halter and lead on so I can tip his nose towards me, which will keep him from swinging his hindquarters towards me while I'm working back there.
And while he was tied, he did another baby horse thing. When his (very short) patience for the work was exhausted, he started pawing. I just stood there like a statue next to him, and waited, and waited, while he pawed and pawed. The instant he stopped pawing I praised him and let him loose to go back to his hay. He ties well in the sense that he doesn't pull back, but he's restless and tends to want to swing his body from side to side - we'll be working on those things too.
To also make the point to him that I can ask him to work even when he'd prefer to eat or do something else and even when he's loose, we then did a little bit of turn on the forehand work. I put one hand on his nose, slightly tipped his head towards me and cued him to move his hindquarters by touching his side. We did this a couple of times in each direction, and then I let him be.