Class Six and the Nits of Doom

Class six's teacher is a witch. That's bad. The dancing skeletons and pterodactyls they can see in her eyes are worse. And nobody likes the snake in her desk. But worst of all are the witch-nits. Rodney catches them first. It's not long before the whole class is scratching. Then strange things start happening to them. The green glowing toenails. The antennae that pick up digital radio. And whatever it is that Rodney's turning into ... is there any cure for the nits of doom?