Composting issues and solutions- Maggots 

The Black Soldier Fly maggots are prolific creatures and they appear in all compost heaps. they are nature's scavengers and good for composting. The Black Soldier flies have no mouth and cannot transmit pathogens, so they are harmless. Black soldier fly larva can consume twice it's weight in food everyday. They suppress the lifecycle of the pest carrying housefly.They usually finish their work and get decomposed in the pile ,they only come out when there is too much moisture. 

Maggots are actually good for composting but if you don't like the sight of them then follow these steps:

1.  Maintain moisture level in the bin by using an adequate amount of browns (crushed dry leaves, compost maker powder  or plain coco peat).

2. Add neem powder or turmeric to the bin. They help reduce bugs and maggots. 

3. Add microbes to the pile, this will speed up decomposition and increase the temperature of the pile. Since maggots die above 40 degrees centigrade, this can control their population to an extent.