I was completely shocked, that after the first full shampoo bath ever, my horse never rolled. I have hosed him down on hot days and washed a bit more thoroughly when sweaty after work, but never shampooed before. Either way, he doesn't roll after a bath. However, lately I see him in a mud spot every day. Just laying down and rolling over occasionally.. even though there are plenty of dry spots.
But I had a grey mare that rolled the moment she set foot in her pasture. The dirt patch at the gate was the best thing.
I play games with Hulk and a fire breathing dragon.. Love it.