The short answer
Bed bug eggs are pearly white, slightly curved and about 1mm long, roughly the size of a pinhead. They are glued into seams, cracks and joints close to where people sleep, often in small clusters. At normal room temperature they hatch in around one to two weeks, which is why spray treatments are repeated about a fortnight apart.
Adult bed bugs get the attention, but the eggs decide how long an infestation lasts and how the job is done. If you know what you are looking at, you can tell a pest controller something useful, and you will understand why the treatment is planned the way it is.
What bed bug eggs look like
- Size: about 1mm long. Think of a pinhead or a grain of salt.
- Colour: pearly or milky white, a little shiny when fresh.
- Shape: a slightly curved oval, like a tiny grain of rice, with a small cap at one end where the young bug comes out.
- Arrangement: usually stuck down in small groups rather than one at a time.
A few days before hatching, an eye spot can show through the shell as a dark dot at one end. Empty shells left behind after hatching are flatter, duller and often split at the capped end.
Eggs are much easier to see on dark fabric or bare wood than on a white mattress cover. Use a bright torch held low and to one side, so the eggs throw a small shadow.
Where they are laid
A female bed bug lays her eggs close to where she feeds and hides, and glues them in place so they cannot be brushed off easily. In a typical bedroom that means:
- in the seams and piping of the mattress,
- in the fabric, staples and corners of a divan base,
- in screw holes and joints of the bed frame and headboard,
- behind loose skirting, in cracks in wood and under the edge of carpet near the bed.
Because the eggs are cemented down, a quick vacuum does not reliably shift them. That is one reason home efforts often seem to work for a week or two and then fail.
How long they take to hatch
Under normal room conditions, bed bug eggs usually hatch in around one to two weeks. They develop faster in a warm room and slower in a cold one. A female can lay a few eggs a day over her adult life, so a small problem left alone for a couple of months becomes a much bigger one.
What hatches is a nymph: a young bed bug, about the size of the egg it came out of, pale and almost see-through until it has fed. It needs a blood meal before each of its five moults to grow into an adult.
Why eggs matter for treatment
Spray treatments
Many insecticides used on bed bugs work far better on the bugs themselves than on eggs. So a firm treats the room, waits for the eggs that survived to hatch, then comes back and treats again before those young bugs are old enough to lay eggs of their own. That is why a spray course is normally two or three visits about a fortnight apart, and why you should not miss the second visit even if the bites have stopped.
Heat treatment
Heat kills eggs as well as bugs, as long as the heat reaches them and stays long enough. That is the main reason people pay more for heat: it can deal with the problem in one visit instead of several. The catch is getting heat into the places eggs are laid, which is why a good firm puts probes inside mattresses, sofas and bed bases. Our heat treatment page explains how a heat job runs.
Steam
Steam kills the eggs it touches directly. It is useful on mattress seams and sofas, but it does not reach deep into furniture or wall gaps, so it is normally used alongside another treatment rather than on its own.
Could it be something else?
Plenty of things are small and white. Before worrying:
- Lint and fluff is soft and pulls away easily. Eggs are firm and stuck.
- Dandruff or skin flakes are flat and irregular, not neat ovals.
- Moth eggs are found on wool and stored clothes, not in mattress seams.
- Carpet beetle larvae are furry, brown and move.
If in doubt, press clear sticky tape over it, stick the tape to dark paper and show it to a pest controller.
What to do if you find eggs
Finding eggs means bed bugs are breeding, so this is a job for a professional rather than shop-bought products. In the meantime:
- put bedding through a hot 60°C wash and a hot dryer cycle,
- bag anything you cannot wash and keep it in the same room,
- do not throw the mattress out without speaking to a firm first, and
- keep sleeping in the same bed so the problem does not spread.
To see what a treatment is likely to cost for your home, try the price checker. If you want us to find a local Sheffield firm to inspect, the form below takes a couple of minutes.