“I have found these “worms” on the roof of my extension”, writes this reader about the thick, grayish green, worm-like creature pictured below. “They only come out when it rains, but there are lots of them! What are they? How can I get rid of them?” Firstly, we want to commend our reader on the excellent photo she sent in, as well as the helpful context and excellent questions. Secondly, we have come to an identification of this creature. We think she found a cranefly larva. Crane flies, typically referred to as ‘flying daddy long legs’ or giant mosquitoes, are neither of these two creatures: neither spiders nor mosquitoes. Which is a good thing! Crane flies are completely harmless to humans and pets.