A decade ago, two brothers started recycling food waste into feed for animals by letting the food chain run its natural course. In other words—they got into the maggot business. Now their South Africa-based company, AgriProtein, is planning to expand its fly farms into an international network, CNN Money reports.

Jason and David Drew founded their company in 2008 with the goal of cultivating fly larvae (a.k.a. maggots) as an eco-friendly protein source. Today, many farmed animals, such as fish and chicken, are fed fish meal: a type of feed made from dried and ground-up fish. Fish are a cheap protein source, but the high demand for animal feed has led to them being harvested at an unsustainable rate.

AgriProtein's solution to the feed industry's sustainability problem involves tapping into a resource that can be found wherever there's food waste. To create its products, the company's two fly factories in Cape Town and Durban each take in 276 tons of food waste every day. The flies lay 340 million eggs on the waste daily, and those eggs hatch into the maggots used to make the feed.

Theoretically, the process could have wide-reaching effects at every stage of the agriculture industry: Human-generated food waste that would otherwise rot in a landfill is used to nourish the protein, which is then used to feed livestock, which ends up as food for humans.

The Drew brothers' "nutrient recycling" concept attracted research funding from the Bill and Melinda Gates Foundation, and today AgriProtein is valued at more than $200 million. The fly farms are limited to South Africa for now, but the company plans to open 100 factories in Asia, the Middle East, Europe and the United States. If their efforts are successful, the brothers could inspire other insect farmers to embrace the maggot revolution.

[h/t CNN Money]