What Do Daddy Long-legs Eat?

Cellar spiders are spiders in the Pholcidae family, comprising almost 2,000 different species. Often called daddy long-legs because of their incredibly long, thin legs and small, fragile bodies, these arachnids are found globally, inhabiting dark, quiet, and damp areas, both indoors and in natural settings like caves and under rocks. Cellar spiders are harmless to humans, with short fangs that cannot pierce human skin. Daddy long-legs act as natural pest control in homes by feeding on a wide variety of small insects, arachnids, and organic debris. Continue reading to discover what daddy long-legs eat.

What Foods Do Daddy Long-legs Eat?

Daddy long-legs are opportunistic, carnivorous predators that eat small insects such as flies, mosquitoes, gnats, moths, and ants. They are adept at catching other spiders, including much larger species like wolf spiders and even black widows. They also eat a variety of insects found in homes, including houseflies, mosquitoes, moths, gnats, ants, beetles, silverfish, and fruit flies.

Because they feed on insects and other spiders, including venomous ones like black widows, daddy long-legs are a form of natural pest control. Although they can clutter basements and nooks with their messy, dust-collecting webs, they are harmless to humans and pose no health risks.

How Do Daddy Long Legs Hunt?

Cellar spiders are versatile predators that may trap or ambush their prey. They build loose, non-sticky webs to trap insects, but they also invade other spiders’ webs, vibrating the web to mimic trapped prey.

Like many other spiders, daddy long-legs produce webs in which to capture their prey. These webs are often created in places with little light and a low chance of being disturbed. Buildings with attics, basements, and tall ceilings are common places for daddy long-legs to set up. They also build webs outdoors in protected areas such as sheds, woodpiles, under decks, in caves, and in rock crevices.

Although many spider webs are sticky, the web of the daddy long-legs is not. Instead of using adhesive silk to capture prey, cellar spiders create messy, chaotic, and irregular three-dimensional tangled webs that trap insects.

A daddy long-legs may also invade another spider’s web, vibrating it to mimic trapped prey. When the other spider returns to its web, the daddy long-legs will ambush it.

Daddy long-legs also use vibrations as a defense mechanism to blur their outline and confuse predators. They also actively shake their webs to further entangle captured prey and, occasionally, mimic trapped insects to lure other spiders to their webs.

Who Competes with Daddy Long Legs for Food?

Daddy long-legs are not the only spiders that like to creep around in damp, dark places and eat other insects and arachnids. They face a fair amount of competition for food, especially from their own species. Some of their primary food struggles come from:

• Other spiders, sometimes other daddy long legs
• Birds
• Wasps
• Dragonflies
• Lizards
• Scorpions
• Snakes

As one might imagine, when daddy long legs cannot find the right insects to feast on, they turn on other arachnids and eat them instead. In terms of food competition, male daddy long-legs often have the advantage over females because they grow more quickly. When a larger spider living in proximity to others detects prey, it has a higher chance of successfully eating that prey compared to smaller spiders.  

Some studies have suggested that environmental conditions, such as food availability, can influence molting patterns in cellar spiders, but clear sex-specific differences in extra molts are not well established.

What Predators Eat Daddy Long Legs?

Like other arachnids, daddy long-legs have numerous predators, including:

• Jumping spiders
• Other daddy long legs (in low-food situations)
• Birds
• Frogs
• Lizards
• Small mammals
• Centipedes

Although humans do not eat them, people will still frequently kill cellar spiders out of fear or when they find their webs in inconvenient places.