Not a pinhead

The camera's one eye is better than my two, even augmented by a big lens. I spent the afternoon searching for the pinhead hermit crabs in my tank, trying to get them to come to the glass, and then to sit still for a minute, long enough for the camera to find them and focus. (Okay, half a minute? Please? If I give you some yummy food?)

They weren't interested. But a couple of their slightly larger friends took the bait. And the shrimp pellets make a good measuring stick, 3 mm. (1/8 inch) long.

The pellet is almost larger than the hermit (sans shell).

These tiny hermits are orange and white. They have the eyes, antennules (those waving flags in the middle of the forehead) and banded antennae of the hairy hermits, but an adult hairy is green or brownish, with blue patches on his knees.

A young adult hairy hermit, turning green already. Big enough now to hold the pellet in her chelipeds.

Side view of the same hermit. Look closely: the shell is populated with tiny tentacled critters, visible from the side and also from the top. The "tail" is one tentacle of a two-tentacled worm who has taken up residence in a tiny hole. 

I'll make another attempt to get photos of the pinhead* hermits. Their colours are contrasting dark brown and white.

*And I measured a standard dressmaking pin's head; it's 1 mm. across. Now, how will I convince a hermit to pose with a pin?