MAG is the larva of flies (Diptera). It is particularly suitable for the larvae of brachynchus, such as housefly, cheese fly and fly fly, rather than the larvae of nematodes, such as mosquitoes and crane flies. A 2012 study estimated that North America alone had more than 300 x 103 trillion

Anglers use what is usually provided by commercial suppliers to catch non predatory fish. Angle is the most popular bait for European anglers. Anglers throw a small amount of fish into the "swimming area" they aim at, attracting the fish to the area. Then, the angler will use the largest or most attractive MAG on the hook in order to be invincible to the fish. Commercial breeders in the UK sell their mags to deal with dealers across the EU. And North America.

In North America, it is mainly used as ice bait. Recently, however, anglers have begun using them throughout the year.