What Lays Eggs in the Ground? A Look at Animals That Lay Eggs Underground

Have you ever been working in your garden and stumbled upon a strange egg buried in the soil? If so, you may be wondering what animal could have laid it there. It turns out, there are several creatures that lay their eggs underground for protection and warmth In this article, we’ll explore some of the most common animals that lay eggs in the ground and why they do it.

Turtles

One of the most well-known animals that lays eggs underground are turtles. Many species of turtles dig nests in sandy banks or soil to bury their eggs. For example, the common snapping turtle digs nests up to 4 inches deep to lay and bury between 20 to 40 eggs.

Turtles lay their eggs in the ground for several important reasons

• Protection from predators – Buried eggs are hidden from animals like raccoons, foxes and birds that may eat them. The soil helps insulate and protect the eggs.

• Stable temperature – Underground, the eggs are shielded from extreme weather fluctuations and maintain a steady incubation temperature which is key for development.

• High humidity – The moist soil keeps the turtle eggs from drying out, which is essential for survival.

• Hatchling safety – When the eggs hatch, the baby turtles are already safely underground. They can dig their way up through the loose soil.

So for turtles, laying eggs underground is an adaptation that greatly improves the survival rate of their offspring. The mother turtle finds a spot, digs a hole, lays her eggs inside, covers them up, and leaves them to incubate safely hidden away.

Crocodilians

Crocodiles, alligators, and caimans all build nests and lay their eggs in the ground. After mating, the female will use her back legs to dig a hole in a sandy bank, digging several feet deep. She lays between 20 to 80 eggs, depending on the species. The eggs are white and leathery, about the size of a goose egg. Once the eggs are securely buried, the warmth from the sun and decomposition of plant material underground incubates the eggs.

Like turtles, crocodilians bury their eggs for protection and proper incubation:

• Guarding the nest – Female crocodilians will fiercely protect the nest during the three month incubation period. Burying the eggs helps conceal them.

• Temperature regulation – The warmth of the surrounding earth keeps eggs between 82-92°F which is ideal for development.

• Preventing water damage – Crocodiles build nests above the water table to avoid flooding which would drown the eggs. Underground shields them.

• Softening shell – The moist earth softens the leathery shell over time so hatchlings can break out more easily.

So nesting underground has clear advantages for crocodilians when it comes reproduction. The eggs and babies are safer from threats underground.

Scaly-Foot Snail

The scaly-foot snail (Chrysomallon squamiferum) is a rare species of sea snail that lives around deep sea hydrothermal vents in the Indian Ocean. Surprisingly, these snails lay their eggs underground in the loose volcanic sediment near the vents.

Female scaly-foot snails hold fertilized eggs in a pouch for several weeks then deposit them about 1-2 inches below the sea floor. The eggs have a jelly-like coating that hardens once they contact sea water which protects them.

Hatching can take over a year in the cold deep sea temperatures. When ready, the young snails work their way out of the sediment. Burying the eggs helps:

• Guard the eggs – Protects from predators in the deep ocean that might eat them. Being underground conceals them.

• Insulation – The rocks and soil insulate the eggs and retain heat given off by nearby hydrothermal vents.

• Prevent drift – Anchors the eggs in place so they aren’t swept away by deep sea currents.

So for these unique snails, laying eggs below the ocean floor helps provide safety, warmth, and stability for the next generation.

Insects That Lay Eggs Underground

Many insects also lay their eggs in the soil. For example:

• Cicadas – Female cicadas use their ovipositor to deposit eggs in slits they make in tree roots underground.

• Centipedes – Centipede mothers lay eggs in holes in damp soil. The females guard the nest and care for the young when they hatch.

• Ground beetles – Ground beetles bury their eggs in the soil. The larvae hatch out and live underground before emerging as adults.

• Earthworms – Earthworms emerge and lay eggs on the surface in cocoons which later get drawn underground. The baby worms hatch underground.

As with other animals, insects gain advantages by laying eggs underground:

• Protection – The soil shields the eggs from predators, parasites, and harsh weather.

• Moisture – The humid environment underground prevents the eggs from drying out.

• Stable temperature – The subterranean location maintains a steady temperature for development.

• Food source – When the eggs hatch, the larvae have an immediate food source from decaying matter in the soil.

So while it may seem strange, laying eggs underground is actually clever parenting in the insect world.

Why Do Birds Not Bury Their Eggs?

Now you may be wondering – if laying eggs underground has so many benefits, why don’t birds do it?

There are a few key reasons:

• Oxygen needs – Developing bird embryos require a lot of oxygen supplied through the porous eggshell. Buried eggs would suffocate.

• Parental care – Most birds actively sit on the eggs to provide warmth and protection. Hard to do underground.

• Identification – For birds that nest in colonies, exposed eggs help parents identify their own.

• Hatching ease – Chicks use their egg tooth to peck out of an exposed egg which is difficult if buried.

• Clean environment – Open nests allow parents to remove egg shells and fecal sacs which reduces disease risk.

So while burying the eggs would provide some protection, it does not suit the physiology and parental habits of birds. Most species have adapted to build open, off-the-ground nests. However, some specialized birds like megapodes and maleo do lay eggs in soil mounds or burrows.

Discovering Buried Eggs

If you find a strange buried “egg” while digging in your garden, there are some clues to its source:

• Size – Turtle eggs are ping pong to tennis ball sized, while insect eggs may be very tiny.

• Shape – Turtle eggs are rounded spheres. Insect eggs come in all shapes like elongated sacs or cylinders.

• Texture – Turtle or crocodile eggs have a leathery, flexible shell. Insects likely have a smooth, hardened outer layer.

• Nest – Look for accompanying nests nearby which may offer hints like a turtle nesting mound or centipede burrow.

So inspect the egg closely and look around the area for context. With some detective work, you can likely determine what animal laid its eggs underground. If they haven’t yet hatched, be sure not to disturb them! Let nature take its course.