Room temperature: about 14 days at 21 °C and 9.1 days at 23 °C (Johnson 1941); Virginia Tech: 60% hatch by day 6 and over 90% by day 9 above 70 °F. No hatching below 13 °C or at 37 °C. Cold eggs survive weeks: half die after 11–34 days at 1–12 °C. Looks: 1 mm, pearl-white, eye spot after 5 days (EPA).
How long do bed bug eggs take to hatch?
About one to two weeks at room temperature. In Johnson's classic measurements (1941), bed bug eggs took an average of 9.1 days at 23 °C (73 °F), 5.9 days at 27.5 °C and about 4½ days at 30–35 °C, while cooler eggs slowed right down: 20.9 days at 17.8 °C and 48.7 days at 13 °C. Below 13 °C (55 °F) and at 37 °C (99 °F), none hatched. So how long do bed bug eggs take to hatch depends almost entirely on temperature — Johnson found humidity made no difference.
Modern figures agree. Virginia Tech reports that at room temperature (above 70 °F) "60% of the eggs will hatch when they are 6 days old; >90% will have hatched by the time they are 9 days old", and a 2011 life table at 26 °C measured an egg stage of 5.4–6.3 days (Polanco, Brewster & Miller). About 97% of eggs hatch under good conditions (Virginia Tech).
| Temperature | Average egg stage | Typical window | Note |
|---|---|---|---|
| 13 °C (55.4 °F) | 49 days | 40–54 days | Threshold: only 2 of 586 eggs hatched |
| 14 °C (57.2 °F) | 41 days | 34–45 days | Extremes 22–52 days |
| 16.1 °C (61 °F) | 29 days | 24–32 days | Johnson Table 2 |
| 17.8 °C (64 °F) | 21 days | 17–23 days | Johnson Table 2 |
| 21 °C (69.8 °F) | 14 days | 11–15 days | Interpolated |
| 23 °C (73.4 °F) | 9.1 days | 7.6–10 days | Extremes 3–14 days |
| 25 °C (77 °F) | 7.7 days | 6.4–8.5 days | Interpolated |
| 27.5 °C (81.5 °F) | 5.9 days | 4.9–6.5 days | Johnson Table 2 |
| 30 °C (86 °F) | 4.8 days | 4–5.3 days | Johnson Table 2 |
| 34 °C (93.2 °F) | 4.5 days | 3.7–5 days | Johnson Table 2 |
| 35 °C (95 °F) | 4.6 days | 3.8–5 days | Johnson Table 2 |
| 37 °C (98.6 °F) | No hatching | — | No egg hatched (Johnson 1941) |
The "typical window" reflects Johnson's finding that the average varied from about 0.83 to 1.10 times the mean, depending on how long after her blood meal the female laid the egg; individual eggs ranged even more widely (3–14 days at 23 °C). That's the bed bug eggs hatching period the timer uses.
Put another way: how long does it take bed bug eggs to hatch at 21 °C (70 °F)? About 14 days. How long does a bed bug egg take to hatch in a warm 27 °C bedroom? About 5.9 days. How long does it take a bedbug egg to hatch in a cold spare room at 14 °C? About 41 days — and below 13 °C it won't hatch until it warms up. People also ask how long does it take for bed bugs to hatch, how long do bed bugs take to hatch or how long does it take bedbugs to hatch; the table and timer answer each.
What happens after the eggs hatch
A newly hatched nymph is about 1.5 mm long and needs a blood meal before it can grow. It won't usually feed in its first day or so — under 24 hours at 25 °C, 1–2 days at 23 °C, about 4 days at 18 °C (Johnson 1941) — and without a meal it survives about 20–58 days at 21 °C. The timer shows both dates. For the rest of the journey to adulthood, see the bed bug life cycle calculator.
What bed bug eggs look like and where they're laid
What do bed bug eggs look like? The EPA describes them as "tiny, the size of a pinhead", "pearl-white in color" and "marked by an eye spot if more than five days old". They are slightly elongated, with a small cap at one end where the nymph pushes out.
Bed bug egg size
The bed bug egg size is about 1 mm (EPA) — roughly a pinhead or a grain of salt. That's visible to the naked eye, but only just, and pale eggs on a pale mattress seam are easy to miss. A torch held at a low angle helps.
Where do bed bugs lay eggs?
Where do bed bugs lay eggs? Mostly where they hide: within about 8 feet of where people sleep, in mattress seams, box springs, bed frames, headboards and cracks (CDC). But Virginia Tech notes that eggs "can be laid singly or in groups", and "a wandering female can lay an egg anywhere in a room". The EPA warns that bed bugs and their eggs can hide in laundry hampers.
Bed bug eggs vs dandruff or lint
Telling bed bug eggs vs dandruff or lint apart comes down to the features the EPA lists: bed bug eggs are a consistent pinhead size, pearl-white, a regular slightly elongated shape, and from about day five show a dark eye spot. They're usually stuck in place in seams and crevices, often with other bed bug signs nearby — shed skins, live bugs or dark spots. Flakes of skin and fluff don't have a regular shape or an eye spot and brush away easily. If you're unsure, a licensed pest professional or your local extension service can identify them.
How long can bed bug eggs survive?
At room temperature, an egg's life is simply its time to hatch — one to two weeks. The interesting question is the cold. How long can bed bug eggs survive below the 13 °C hatching threshold? Johnson (1941) kept eggs at 1–13 °C and then warmed them to see how many still hatched:
| Temperature | Half the eggs dead after | 99.99% dead after (calculated) |
|---|---|---|
| 1 °C (33.8 °F) | 11–12 days | 39–40 days |
| 4 °C (39.2 °F) | 18–26 days | 47–66 days |
| 7 °C (44.6 °F) | 24–30 days | 50–68 days |
| 9.1–9.8 °C (48–50 °F) | 24–28 days | 51–62 days |
| 12 °C (53.6 °F) | 20–34 days | 44–80 days |
So how long can bed bug eggs live in a cold room? Weeks to a couple of months: half die after about 11 days near freezing and after 20–34 days at 4–12 °C, but some can last nearly 80 days at about 12 °C. Eggs held at a slowly fluctuating 11.5 °C didn't hatch in 80 days, though eggs that had nearly finished developing could still hatch at 8 °C. How long do bed bug eggs live and how long do bed bug eggs survive in a heated home? Until they hatch, about a week or two. How long can bed bug eggs last if a room is cold all winter? Most of a couple of months; warm them up before then and the survivors hatch.
Cold below freezing is a different matter: bed bug eggs don't freeze until about −30 °C, but long exposure kills them. Eggs are also more heat-resistant than adults. Exact kill temperatures and times are on what temperature kills bed bugs.
How many eggs do bed bugs lay?
How many eggs do bed bugs lay? Fewer than many websites claim, but a steady stream:
- Per day: 1–7 eggs a day for about 10 days after a single blood meal (Virginia Tech). A 2011 life table at 26 °C measured 0.64 daughter eggs per female per day over her life — and since about half of eggs are male (Virginia Tech), roughly 1.3 eggs a day in total (Polanco, Brewster & Miller).
- Per meal: 5–20 eggs (Virginia Tech); in Johnson's (1941) tests at 23 °C, an average of 8.9 from the first adult meal and 6.3 from the second.
- Per lifetime: about 140 eggs in modern Virginia strains (Virginia Tech).
- Timing: at 23 °C a female starts laying 5–6 days after feeding and keeps going for 8–10 days (Johnson 1941). Below about 13 °C she stops laying.
The more often she feeds, the more eggs she lays (Virginia Tech). Repeated mating cuts egg production: females mated only once laid 25% more eggs.
Do bed bug eggs survive washing and drying?
Not a hot wash or a hot dryer. Naylor and Boase (2010) found that washing at 60 °C, tumble drying on a hot cycle for at least 30 minutes, and dry cleaning all killed every life stage, eggs included — but soaking for 24 hours did not affect the eggs. The University of Minnesota advises 30 minutes in the dryer at the highest heat the item can take. A cool wash on its own isn't enough to rely on, so follow it with a hot dry. For exact heat and freezer times, see what temperature kills bed bugs.
How this egg hatch timer works
- Hatch time: the average egg stage from Johnson's (1941) constant-temperature table, with straight-line interpolation between his measured temperatures (13–35 °C). The window is 0.83–1.10 times that average, from his data on eggs laid at different times after a meal. Dates count from the day you enter.
- 13–14 °C: shown as "very few hatch", because at 13 °C only 2 of 586 eggs did.
- Below 13 °C: no hatching; the result shows how long eggs survive from Johnson's Table 15.
- Below 0 °C or above 35 °C: the cold or heat kill time from the shared bed bug data (Olson et al. 2013; Kells & Goblirsch 2011); at 37 °C no eggs hatched.
- First meal and survival: the earliest feeding time after hatching from Johnson (1941), and first-stage nymph survival with no meal from the same starvation data as our other bed bug pages.
The egg times are the same ones the life cycle calculator uses, so the two pages always agree.
Frequently asked questions
How long do bed bug eggs take to hatch?
About 1–2 weeks at room temperature: 9.1 days on average at 23 °C, about 5–6 days at 26–28 °C and up to 7 weeks at 13 °C (Johnson 1941). Virginia Tech: over 90% hatch by day 9 above 70 °F.
How warm does it need to be for bed bug eggs to hatch?
Between 13 °C and 35 °C. None hatched below 13 °C or at 37 °C (Johnson 1941).
How long can bed bug eggs survive?
At room temperature, until they hatch in 1–2 weeks. Below 13 °C they wait: half die after 11–34 days, and calculated total mortality takes 39–80 days (Johnson 1941).
What do bed bug eggs look like?
Pearl-white, about 1 mm (a pinhead), slightly elongated, with an eye spot after about 5 days (EPA).
Where do bed bugs lay their eggs?
Mostly in cracks and seams near the bed, singly or in groups, but a wandering female can lay anywhere in a room (Virginia Tech; CDC).
How many eggs do bed bugs lay in a lifetime?
1–7 a day for about 10 days after each meal, 5–20 per meal and about 140 in a lifetime (Virginia Tech).
Can bed bug eggs survive washing?
Not washing at 60 °C or a hot dryer for 30 minutes (Naylor & Boase 2010). Soaking alone didn't kill eggs.
Does humidity change how long bed bug eggs take to hatch?
No. Johnson (1941) found a wide range of humidity had no effect on the egg stage.
Do bed bug eggs hatch in winter?
Not in a room colder than 13 °C. In a heated home they hatch normally all year.
How soon do newly hatched bed bugs bite?
Usually after a day or so — under 24 hours at 25 °C, 1–2 days at 23 °C, about 4 days at 18 °C (Johnson 1941).
Are bed bug eggs visible?
Yes, just: they're about 1 mm and pearl-white, so they're easiest to spot with a torch held low across seams.
These calculators give estimates from laboratory studies, for education. Real bed bugs vary with strain, insecticide resistance, humidity and how easily they reach a host. Bed bugs are not known to spread disease (CDC), but if bites trouble you, talk to a doctor or pharmacist. For an infestation, contact a licensed pest professional or your local extension service. We give no pesticide advice.