
I myself like to watch to see if a bug I find in my garden is a pest or a benefit because I can use beneficial bugs to help me in the garden. Some flies can aid in controlling other insect pests (hover fly larva kill aphids). Flies also are good pollinators! Only bees and a few wasp pollinate more plants than flies.
I
first found these flies breeding in my compost and just had to look them up to see what they were. They do not bite because they have no mouth parts which also means they cannot eat. Very short life for these flies! You may even say "it's the hard knock life for them";) LoL!!

If you have lots of these in your trash or compost then you will have almost no houseflies around since houseflies hate black soldier flies. Houseflies are the flies that you hate, not these.
These flies are great for breaking down waste! The adults look like mud wasp but I can assure you these are flies.
Benefits:
They eat many kinds of decomposing organic matter, including algae, carrion, compost heaps, manures (rabbit and chicken), mold, plant refuse, and the waste products of beehives like it's candy! They not only eat all that but they also eat meats! That can come in handy if your trying to get rid of bodies! LoL!! Just kidding:)

You can also set them up to self harvest for chicken, fish, frags, etc etc feed. Hope this helps you guys keep these flies around your yard as they are a great benefit!!
God Bless:)