Bugs lay their eggs in many different ways, and those eggs pop out in a fascinating array of shapes and sizes, colors, and textures. Some are smooth and globular, others rough and ridged. Some look like Skittles and others more like Raisinets. Some eggs are transparent, others opaque, and many of them look intriguingly alien. Certain species of bug can even alter the color of their eggs to fit in better with environmental factors.

Scientists at Harvard University, led by geneticist Cassandra Extavour, have begun to explain why the insect world has such variety among its eggs. The team built a database with descriptions of eggs from more than 6,700 insect species, from the largest known variety, laid by the earth-borer beetle, to the smallest, the microscopic egg of the Platygaster vernalis wasp. From that data they determined that the beautiful and wildly different shapes, sizes, and colors of the eggs below are most likely an evolutionary response to the environment in which each insect lays its eggs—for instance in wood, on other natural or artificial surfaces, or glued to the underbellies of leaves.

Butterfly eggs, like these ones from the large white butterfly (Pieris brassicae) can be identified by a small depression at their tops, which has a hole at its center called the micropyle. This is where the sperm enters during fertilization. If you look really, really closely, you'll also notice thousands of tiny, microscopic pores called aeropyles, which are like breathing tubes for the developing larva.
Butterfly eggs, like these ones from the large white butterfly (Pieris brassicae) can be identified by a small depression at their tops, which has a hole at its center called the micropyle. This is where the sperm enters during fertilization. If you look really, really closely, you’ll also notice thousands of tiny, microscopic pores called aeropyles, which are like breathing tubes for the developing larva. Волков Владислав Петрович/CC BY-SA 3.0

Female stick insects can actually produce eggs—like these from a Vietnamese or Annan walking stick (Medauroidea extradentata)—without any kind of fertilization by a male, in a process known as parthenogenesis. Depending on the species, eggs may take between two and 14 months to hatch into nymphs.
Female stick insects can actually produce eggs—like these from a Vietnamese or Annan walking stick (Medauroidea extradentata)—without any kind of fertilization by a male, in a process known as parthenogenesis. Depending on the species, eggs may take between two and 14 months to hatch into nymphs. Geza Farkas/Shutterstock.com
The eggs of the Chrysomela populi, the red poplar leaf beetle, are laid in clusters. They are also prone to sibling egg cannibalism, which is just what it sounds like.
The eggs of the Chrysomela populi, the red poplar leaf beetle, are laid in clusters. They are also prone to sibling egg cannibalism, which is just what it sounds like. D. Kucharski K. Kucharska/Shutterstock.com
These eggs, resembling a ninja's iron spike ball, belong to the stink bug (Podisus maculiventris). The momma stink bug actually has the ability to choose the color of her eggs. The coloring ranges from pale yellow to black, depending on the surface on which she lays them. In addition, stinkbug eggs have little blobs on top that are nutrient-rich and attractive to ants, which incentivizes ants to carry the eggs off and store them with their food. The eggs hatch in the comfort and protection of the ant colony—and interestingly, when they first hatch, the bug larva even resembles ants.
These eggs, resembling a ninja’s iron spike ball, belong to the stink bug (Podisus maculiventris). The momma stink bug actually has the ability to choose the color of her eggs. The coloring ranges from pale yellow to black, depending on the surface on which she lays them. In addition, stinkbug eggs have little blobs on top that are nutrient-rich and attractive to ants, which incentivizes ants to carry the eggs off and store them with their food. The eggs hatch in the comfort and protection of the ant colony—and interestingly, when they first hatch, the bug larva even resembles ants. Nik Br/Shutterstock.com
These tiny, tawny eggs belong to the red-shouldered stink bug (Thyanta custator).
These tiny, tawny eggs belong to the red-shouldered stink bug (Thyanta custator). Therese15/Shutterstock.com
Likely the eggs of the horned squash bug (Anasa tristis).
Likely the eggs of the horned squash bug (Anasa tristis). aroonrojkul/Shutterstock.com
Resembling miniature melons, these eggs of the pentatomid bug (Holcostethus limbolarius) are being scoped out by a Scelionid wasp.
Resembling miniature melons, these eggs of the pentatomid bug (Holcostethus limbolarius) are being scoped out by a Scelionid wasp. gbohne/CC BY-SA 2.0

This story has been updated to include new research on insect eggs.

This story originally ran in 2016; it has been updated for 2022.