The tiny ones are deer ticks. They are about the size of the head of a pin. I've had them on my cats so small that I had to use a magnifying glass and tweezers to make sure it was a bug and not dirt as I pulled them off. The orange kitty had them around his eyes, ears, nose and mouth constantly. They showed up really well on him than the darker cats. The deer ticks are the main ones known for carrying Lyme disease.
Great... Hope mine weren't carriers! Weird that I'd never seen that type before. Usually I get the ones that are about 1/8" in diameter or so.