Why can't i tame these horses minecraft?

I'm in creative mode and i spawned a but ton of horses, i know how to tame horses but they won't even let me get on the to tame them!

I could never tame them on creative mode. Try going to survival.
Also note that you'll get thrown off quite a few times before they're tame. You'll know you've succeeded when they spew hearts like other mobs do when they breed.