* Algae: They scrape algae off rocks and plants using their mouthparts.
* Small aquatic invertebrates: This includes other insects like mosquito larvae, water fleas, and even other water boatmen.
* Dead organic matter: They also scavenge on dead insects and other decomposing materials.
Their feeding behavior can vary slightly depending on the species and the availability of food in their environment. But generally, they are opportunistic feeders that will take advantage of any available food source.