I came up behind two horsists today on my way home, had to wait for a passing place in the lane go gou round them, so was creeping at 5mph. One of the horses started going a bit wild as I approached to pass them. I wonder if, much like the rcumbent, EVs are not familiar to them and get interpreted as hostile (imagine a big red monster creeping up on you almost silently, just the sound of its breathing).