See how you're focusing PAST the glass? The rock is getting more and more in focus the further away it gets, then some of the algae looking stuff is almost completely in focus? That's how close to your lens your camera is able to focus, most likely, so try scooting the camera back from the tank more.
Also, if you're autofocusing it may just not be picking up the worms at all and instead focusing on the farther back rocks. Try sticking a piece of paper right next to the worms and have the camera focus on that. As long as the paper is flat against the glass, this will also bring the worms pretty well into focus, not perfect maybe but a lot better than you've got now.
Or if you can manual focus, just focus as close as you can to the camera, then move your camera closer or farther from the tank until you've got something in focus.