Do you suffer from maggots in the container, put there a pantyhose filled with mothballs in ... That seems to work very well!
Do you suffer from maggots in green or gray tray, sprinkle sand on the edge of the box so that the flies do not lay eggs. Should you have maggots in the bin, big shovel sand throw in the bin. Maggots are slimy and so die.
Do you suffer from maggots, anywhere ... with salt they die! Salt along the edges of the bin helps to keep the maggots in the bin.
Maggots do not like light so wheelie bin with a piece of wood left open.