Spider Motherhood: Protecting Egg Sacs

Many people are surprised to learn that spiders exhibit a range of behaviors that indicate maternal care, particularly when it comes to protecting their egg sacs. Spider mothers are often fiercely protective, putting their lives on the line to safeguard their offspring.

Will a Mother Spider Protect Her Egg Sac?

The answer is a resounding yes. Whether it's a wolf spider, a tarantula, or any other spider species, maternal protection of the egg sac is a common behavior. The degree of protection, however, can vary depending on the species.

Wolf Spiders: Carrying and Protecting

Wolf spiders carry their egg sacs attached to their spinnerets and protect the sac until the eggs hatch. These spiders are known for their unwavering commitment to their young, often remaining near the sac until the spiderlings emerge.

Tarantulas: Vigilant and Fierce

Tarantulas create silk egg sacs and guard them fiercely. They often remain close to the sac until the spiderlings emerge, displaying remarkable dedication and fierce defense.

Orb-Weaving Spiders: Strategic Placement

Orb-weaving spiders may not guard their egg sacs as closely but they often place them in safe locations to minimize predation. While their guarding behavior may not be as intense as other species, their strategic placement shows a similar level of maternal care.

A Personal Encounter

One memorable encounter involved a pregnant spider at my condo in Batangas, Philippines. Although I have yet to identify her species, her body, measuring around 10 cm (about four inches), carried an egg sac approximately 7 cm across and about 2 cm thick. The spider's determination and readiness to pounce if I approached prompted me to respect her space.

Spiders' Survival Strategy

Spiders are well-equipped to protect their egg sacs. For instance, when large spiders feel threatened, they can release a significant amount of venom to deter predators. Baby spiders, similar to snakes, will also bite and hold on to defend their sac.

Common Protection Methods

Almost all female spiders protect their eggs by making a silk bed and then covering them with a silk blanket. They further wrap the eggs in more silk to create the egg sac and hang it in a safe location. The mother then guards the sac until the babies hatch, ensuring their survival.

If you are an entomologist and can identify this pregnant spider, please share your expertise in the comments below!