You might become concerned, or possibly even grossed out, if you discover "large maggots" thriving in your compost pile. But, don't worry, you're just reaping the benefits of a valuable decomposer of organic matter, Soldier Fly larvae (or Black Soldier Fly larvae).
Soldier Fly larvae are about an inch long and are white-ish to dark brown in color. They are typically very active in the compost pile and thrive on moist nitrogen-rich materials such as vegetable and fruit scraps. If you have a large number of Soldier Fly larvae in your compost, listen closely and you can hear the chorus of their collective "munching".

The Soldier Fly larvae are harmless in your compost pile; again, they are very beneficial in turning organic matter into "black gold" compost that you can use in your garden or landscape. Plus, the mature Soldier Fly will NOT be a pest or nuisance to you. Soldier Flies look like a small wasp, only live a couple of days, do NOT bite or sting, and do not carry disease; it's likely that you will never notice them.

To read more about the Soldier Fly and Solider Fly larvae, see this article by Carol Savonen, from the Oregon State University Extension web site.

blog entry by Mark Murphy, CMG
photo by Reggie Reeves, CMG