Opening your trash bin and finding dozens of tiny white maggots crawling across the waste can be an unpleasant surprise, especially during hot weather. It may seem as though they appeared overnight, but there is a simple explanation. Maggots are fly larvae, and flies are particularly attracted to moist, decomposing food such as meat, fish, leftovers, fruits, and vegetables.

A fly can lay eggs on exposed organic waste, and warm conditions can help those eggs hatch quickly. That explains why a bin that looked perfectly normal recently can suddenly seem overrun. Moisture, food residue, heat, and easy access make garbage containers especially attractive breeding sites. Fortunately, you don’t need to wait until the problem gets this bad. A few changes in the way you store and dispose of household waste can make your bin considerably less attractive to flies—and one habit matters more than most.