No, That Grass Spider Isn't Dangerous

The grass spider is one of of the most common critters you'll find in your backyard. Part of the Agelenopsis genus, these arachnids are masters at building funnel-shaped webs in dense vegetation and brush piles, where they lie in wait for prey.

Common spiders in North America, grass spiders are often mistaken for wolf spiders or hobo spiders. However, their unique webs and darting movements set them apart.

What Do Grass Spiders Look Like?

Grass spiders are medium-sized spiders with a body length ranging from 0.3 to 0.75 inches (1 to 2 cm) and small fangs adorning the head region. They have long, slender legs covered in fine hairs that help them move quickly.

A bold black line runs along each side of their tan or light brown body, making them easy to identify.

Grass Spiders vs. Wolf Spiders

Unlike wolf spiders, grass spiders have a spinneret — used for web-making — that is visible at the end of their abdomen. The grass spider will typically be found hanging out in its web and waiting on potential prey while the wolf spider scurries along the ground to chase its food.

Their appearance may also be confused with hobo spiders. Neither species is particularly aggressive, but a bite from a hobo will be much more painful and potentially lead to effects like necrotic skin lesions if not urgently treated.

Are Grass Spiders Dangerous?

While they may seem intimidating to some, grass spiders are harmless to humans and do not pose a risk to human skin. Their presence in gardens and fields is a sign of a healthy ecosystem, making them valuable allies in pest control.

Grass Spider Subspecies

Grass spiders belong to the Agelenopsis genus, which includes many species commonly found in North America. These funnel weavers are named for their distinctive funnel-shaped webs and are often found in gardens, grassy fields and wooded areas.

While Agelenopsis species have subtle differences in size and coloration, their behaviors and habitat preferences are remarkably similar. This adaptability has allowed them to thrive in a wide range of environments.

Life Cycle

The life cycle of a grass spider begins when the female lays her eggs in a silk egg sac, which she hides in dense vegetation or under brush piles. When the eggs hatch, the spiderlings disperse and build their own small funnel webs to start catching prey.

Grass spiders grow through several molts, shedding their thin skin as they mature. Adult males live only long enough to mate, while females can survive through the colder months to reproduce again in the spring.

Social Habits

Grass spiders are solitary creatures that spend most of their time maintaining their webs or hunting.

Male grass spiders roam in search of mates during the breeding season, while females remain near their webs to protect their egg sacs. Their interactions are limited to reproduction, after which the males typically die.

These spiders are shy and non-aggressive, preferring to flee rather than confront larger animals, including humans. A spider infestation of grass spiders in a home or garden is usually harmless and often beneficial, as they help control insect populations.

Diet

Grass spiders are carnivorous and primarily feed on small insects, such as flies, beetles and even small butterflies. They use their funnel web to catch their prey, waiting at the narrow end of the funnel for vibrations that signal a trapped insect.

These spiders do not rely on sticky silk like orb weavers. Instead, their webs are non-sticky but highly effective at entangling prey. Once an insect becomes trapped, the spider darts out, injects venom and quickly drags the meal back into the funnel.

Grass Spider Environment

Grass spiders are commonly found in North America, especially in gardens, grassy fields and wooded areas. They prefer habitats with dense vegetation, where they can build their funnel-shaped webs between blades of short grass, inside a rock crevice, or in brush piles.

In urban environments, grass spiders may seek shelter in sheds, garages or homes, often drawn to areas with pet food or insects. Homeowners can reduce the chances of a grass spider infestation by sealing cracks and removing clutter where spiders might hide.

We created this article in conjunction with AI technology, then made sure it was fact-checked and edited by a HowStuffWorks editor.

Original article: No, That Grass Spider Isn't Dangerous

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