bed bug nymph - engorged
bed bug nymph - unfed
Bed bugs develop in stages from the time the egg is laid, through several immature or “nymph” stages, and then to the adult stage. This process is called simple metamorphosis. Other insects, such as fleas, develop by complete metamorphosis and have four stages: egg, larva, pupa and adult. Entomologists would not refer to a bed bug nymph as larvae, but non-experts often assume that bed bug larva is the correct name for a nymph.

More simply, a nymph is a bed bug that hasn’t fully matured into adulthood. It’s helpful to know what immature bed bugs look like since they can leave behind the most evidence.

Pictures of nymphs
As you can see in the pictures, nymphs look like smaller versions of adult bed bugs and have the same flat, seed-shaped bodies.

There are five nymph stages to the bed bug life cycle. At each stage of this gradual metamorphosis, a bed bug requires one blood meal in order to grow, shed its exoskeleton, and mature into an adult bed bug.

Nymphs grow about half a millimeter with each feeding and subsequent morph. In the picture you can see how much a fully engorged nymph grows after hatching. Look at the spent egg casing next to the bug’s blood-filled body.

What you need to know about the bed bug life cycle
While a growing infestation is never a good thing, it can be helpful since spotting adult bed bugs is difficult. Because a nymph molts five times, evidence of five translucent bed bug exoskeletons can be found for each bed bug in your home.

You can also spot bed bug eggs from hatched nymphs. These eggs are white and measure approximately one millimeter or about the size of a grain of rice. They are typically tucked into the piping of your mattress as well as other bed bug hiding spots.

Nymph timetable
Nymphs grow after each feeding, leaving skins in clusters. Under proper conditions, each morph can take about a week. As adults, these bed bugs will take in blood meals every seven to 10 days (all the while mating until your home is completely overrun).

While a nymph won’t advance to the next stage without a blood meal, this doesn’t mean it will die. Nymphs can last for months without feeding, while adult bed bugs can go more than a year. Along with their expert hiding skills, this is why they are so difficult to kill.

It’s time to stop the bed bug larvae talk and get the facts straight. A pest management professional can help you identify the type of infestation you are dealing with and get pests out for good. Call Terminix® and receive a free home bed bug inspection.