What Do Fireflies Eat And Drink?

You see them filling the summer nights with yellow-green flashes; but have you ever wanted to know more about the everyday lives of fireflies? Specifically, what do fireflies eat and drink? What animals eat fireflies? Keep reading! In this article, we’ll answer all of these questions and more.

What Do Firefly Larvae Eat?

What Do Firefly Larvae Eat

Firefly larvae don’t always have the same diet as their adult counterparts. This begs the question, what do these insects eat when they are in the larval stage?

Fireflies spend most of their lives as larvae. They do the most growing and developing while in this stage, so they have to have a diet that promotes this growth.

Firefly larvae are carnivorous little creatures. They eat primarily soft-bodied creatures, including:

  • Snails: Firefly larvae live primarily underground, so they hunt invertebrates that they find naturally in this environment. They will eat the soft bodies of small snails and disregard the shells.
  • Slugs: Slugs are basically snails without shells, which makes them an ideal food choice for firefly larvae. Again, they eat mostly small slugs, as even the largest firefly larvae are no more than three-fourths of an inch long.
  • Worms: Worms spend their lives underground and are often abundant in the soils that firefly larvae call home. Small worms are their favorite, and they eat these regularly.
  • Caterpillars: Many kinds of caterpillars burrow into the soil to pupate. Firefly larvae will sometimes feast on these caterpillars.
  • Other firefly larvae: Many firefly larvae turn carnivorous. Some will eat the larvae of other species, while others will eat their own brothers and sisters–particularly if there isn’t a lot of other food available.

What Do Adult Fireflies Eat?

Adult firefly diets can vary greatly from species to species. Sometimes, they eat the same kinds of foods as their larvae do, but most often, their food choices change significantly once they reach adulthood.

Some fireflies are carnivorous, others are herbivorous, and still others don’t eat anything at all. Let’s take a closer look at these diverse diet preferences:

  • Pollen and nectar: Some fireflies are herbivores and will only eat nectar and pollen from flowers. Some will also eat sugar water from hummingbird feeders, which tastes similar to the nectar they are used to eating.
  • Insects: Some adult fireflies continue feeding on the soft-bodied insects and invertebrates they ate as larvae. Common foods include snails, slugs, and worms.
  • Other fireflies: Some adult fireflies feed on members of other firefly species, as you can see in the video at the end of this section. Specifically, some female fireflies mimic the flashing patterns of other species, drawing males of those species who are interested in mating; when the males get close enough, the females will eat them.
  • Nothing at all: Some fireflies only live for a few short weeks in the adult stage. These fireflies may eat nothing at all during this final period of their lives.

Check out this video about fireflies that eat other fireflies:

Do Fireflies Drink Water?

Fireflies do need to drink some water in order to survive. That said, they get a lot of their water needs from the foods they eat.

Fireflies may occasionally get extra water by sipping from rain or dewdrops that gather on plants. They often live near water sources where the air and soil is more moist, which ensures that they won’t dry out as fast.

During periods of drought or high heat, fireflies may drink more than usual in an effort to replace fluids lost to the environment. On the other hand, they may not need to drink as much additional water during wet or cool seasons because they will get more water from their food and will be able to retain the water better.

What Animals Eat Fireflies?

What Animals Eat Fireflies

Fireflies have built-in defenses against predators. Their blood and exoskeletons contain a number of nasty-tasting compounds that many animals have learned to avoid. 

These compounds are so nasty that various predatory animals have been observed spitting out fireflies unharmed after ingesting them. Others have been known to gag and vomit from the nasty taste, and some types of lizards will even die after eating fireflies.

That said, there are a few animals who like to eat fireflies. These animals include:

  • Frogs: Many types of frogs are notorious for eating fireflies. Some frogs eat so many fireflies that they begin to glow themselves!
  • Spiders: Spiders eat many kinds of insects, and fireflies aren’t safe from these arachnid predators. If they become caught in a spider’s web, most spiders will eat them.
  • Some birds: Many types of birds avoid eating fireflies, but not all of them. Some species of bird seem unaffected by the nasty taste and eat fireflies along with any other insect.


Fireflies eat primarily soft-bodied insects and invertebrates when they are in the larval stage. When they reach adulthood, they may continue eating these creatures, prey on other fireflies, feast on nectar and pollen, or stop eating altogether. Looking for more information about these interesting creatures? Check out this article about where they spend the wintertime.

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