Below is a picture from a customer who asked the question, “What are these in my bin and are they harmful to the worms”? These are probably black soldier fly larvae. They are a little unsightly, but are good composters in their own right and are not harmful to your worms. These tend to show up in my manure piles when the weather heats up. I will remove them most of the time from my worm bin if they show up, but it is not necessary.
Texas Jumpers 