Warm home (21 °C): most should be dead after about 144 days with nobody to bite. Cool home (13 °C): about 463 days, and one adult lasted 562–572 days (Johnson 1941). Occupied home: no bites doesn't mean no bed bugs — some people don't react (CDC). To confirm: interceptor traps checked weekly and inspections for at least a year (EPA).
How long can bed bugs lay dormant?
Bed bugs can sit quietly in cracks for months. With nobody to bite in a home kept at about 21 °C (70 °F), most should be dead after roughly 144 days (4.7 months); in a cool home at 13 °C (55 °F) the same estimate is about 463 days, and one adult in a 1941 study lasted 562–572 days. So how long can bed bugs lay dormant? From about three months in a warm home to well over a year in a cold one.
Those are the same starvation figures that power our no-host calculator — Johnson (1941) for 7–23 °C and Polanco, Miller & Brewster (2011) at 26 °C — so this page and that one always agree. How long can bed bugs be dormant also depends on their stage: the older nymphs and adults last longest, while newly hatched nymphs die within weeks.
Whichever way you ask it — how long can a bed bug stay dormant, how long can bed bugs remain dormant, how long can bed bugs live dormant or how long do bed bugs lay dormant — the useful question is really "could they still be here?" The checker above answers that for your situation.
| Home temperature | Most should be dead after | Longest single bug recorded | What they're doing |
|---|---|---|---|
| 7 °C (44.6 °F) | 367 days (about 12.1 months) | 460 days | Inactive — no spontaneous movement |
| 13 °C (55.4 °F) | 463 days (about 15.2 months) | 562 days | Moving and feeding |
| 18 °C (64.4 °F) | 195 days (about 6.4 months) | 268 days | Moving and feeding |
| 21 °C (69.8 °F) | 144 days (about 4.7 months) | 184 days | Moving and feeding |
| 26.3 °C (79.3 °F) | 128 days (about 4.2 months) | 143 days | Moving and feeding |
"Most should be dead" uses the longest-lasting stage at each temperature; at temperatures other than 26 °C, the older nymphs' figures are estimates that follow the adult pattern (see the starvation calculator for every stage).
What "dormant" really means for bed bugs
Do bed bugs go dormant? Not in the way people imagine. There's no hibernation den and no long sleep. What looks like dormancy is three ordinary things happening together:
- Digesting and hiding. After a meal bed bugs retreat to cracks to digest, and normally feed only every 3–7 days (Virginia Tech). On any day, most of a population is out of sight.
- Waiting for a host. A bed bug with nothing to bite simply stays put and slowly uses up its reserves. Nymphs can't moult without a meal, so they "stay in that current instar until it is able to find a blood meal, or it dies" (Virginia Tech).
- Slowing in the cold. Below about 9–11 °C bed bugs stop moving about on their own (Johnson 1941; Mellanby saw no movement below 11 °C), and below 13 °C eggs don't hatch and females stop laying.
Do bed bugs hibernate?
Do bed bugs hibernate? Entomologists have argued about it. Older writers said bed bugs "do not hibernate in the true sense of the word", but Johnson (1941) found that nymphs kept at 15 °C before feeding often failed to moult even after a meal — a pause he called a "diapause" — and concluded that the old statement "may not be strictly true". What's certain is that cold makes them inactive, not dead: most bed bugs survived three weeks at 0 °C in a 2017 study (Rukke, Hage & Aak). In a heated home, none of this applies — they stay active all year.
How temperature changes how long they stay inactive
Temperature is the dial. A starving bed bug is losing water and burning reserves; warmth speeds both up. Johnson (1941) found that survival rises as temperature falls to about 13–15 °C, then falls again in colder conditions:
- 26 °C (79 °F): most of the hardiest stage gone after about 128 days (Polanco et al. 2011).
- 21 °C (70 °F): about 144 days.
- 18 °C (64 °F): about 195 days.
- 13 °C (55 °F): about 463 days, and single bugs over 560 days.
- 7 °C (45 °F): about 367 days — lower than at 13 °C, because cold itself starts to harm them.
Humidity matters too: in Johnson's tests the shortest survival came from very dry air and the longest from humid air. Packing tightly into cracks helps bed bugs keep a humid microclimate (Virginia Tech). How long can bed bugs go dormant in a cold, damp holiday cottage? Potentially longer than in any table here.
Freezing is different: long, hard cold kills them. That's covered on do bed bugs die in winter.
Can bed bugs come back after months?
Yes. Can bed bugs come back after months? There are three common ways it happens:
- They never left. A small number can go unnoticed. Some people don't react to bites at all, and in those who do, marks can take up to 14 days to appear (CDC). A quiet spell isn't proof.
- They waited. In a cool or empty home, the table above shows they can outlast a long absence — Johnson (1941) noted that people moving back into a long-empty house would most likely meet fifth-stage nymphs, unmated females and males, the stages that last longest.
- Eggs hatched later. Eggs laid before treatment can hatch after it; at room temperature they hatch in about one to two weeks (Johnson 1941). The EPA advises inspecting "at least every 7 days in case any eggs remain".
And of course they can be brought back in: they travel in luggage, furniture and bags.
How to tell if bed bugs are really gone
How to tell if bed bugs are gone: look for evidence over a long enough time, using methods that catch bugs you wouldn't otherwise see. The EPA's guidance is to "keep checking for at least a year after you're done to make sure all the bed bugs are gone". Practical steps from the EPA, CDC and University of Minnesota:
- Interceptor traps under each leg of the bed and sofa — check and clean them every week (EPA).
- Inspect hiding places: mattress seams, box springs, bed frames and headboards, cracks and crevices, behind wallpaper (CDC).
- Keep encasements on the mattress and box spring for a year (EPA). Bugs trapped inside start to die after a couple of weeks but should be left for at least a year to 18 months (University of Minnesota).
- Don't move items between rooms while you're unsure (University of Minnesota).
Signs of dormant bed bugs
Signs of dormant bed bugs are the same as any bed bug signs, just fewer and older: live bugs or nymphs in seams and cracks, pale shed skins, tiny pearl-white eggs and small dark spots of droppings or blood (University of Minnesota; EPA). Fresh signs mean they're active; only old, dried evidence and empty traps for many months suggest they're gone. If you find any live bug, contact a licensed pest professional.
How this checker works
The checker converts the time since your last sign into days (1 month = 30.44 days) and then:
- If someone was living there (or pets were), it can't use starvation times — bugs could have fed — so it says they could still be there and gives the confirmation checklist.
- If the home was empty, it compares the days with the shared bed bug starvation data at your temperature (7–28 °C): "Still likely there" before most of the hardiest stage would be dead, "Possible" between that and the longest single bug recorded, and "Unlikely" after it. These are the same figures as the empty-house planner on the starvation calculator.
The figures are laboratory averages (Johnson 1941; Polanco, Miller & Brewster 2011). Older nymphs were only measured at about 26 °C, so at other temperatures their times follow the adult pattern and are estimates. A result of "Unlikely" is not a guarantee — confirm with traps and inspection.
Frequently asked questions
How long can bed bugs lay dormant?
With nobody to bite, about 144 days at 21 °C before most are dead, and about 463 days at 13 °C. A single adult lasted 562–572 days at 13 °C (Johnson 1941).
Do bed bugs go dormant?
Not in a true sleep. They hide, digest and wait between meals, and in the cold (below about 9–11 °C) they stop moving. In a heated home they stay active all year.
Do bed bugs hibernate?
Not in the usual sense, though Johnson (1941) saw nymphs kept at 15 °C pause their moulting, which he called a diapause. Cold makes them inactive rather than killing them quickly.
Can bed bugs come back after months?
Yes — a few may have survived unnoticed, waited in a cool empty home, or hatched from eggs later. The EPA advises checking for at least a year.
How do I tell if bed bugs are gone?
Use interceptor traps under bed legs and check them weekly, inspect seams and cracks, keep encasements on for a year, and keep checking for at least a year (EPA).
What are signs of dormant bed bugs?
Live bugs or nymphs in seams and cracks, shed skins, pearl-white eggs and small dark spots. Fresh signs mean they're active.
Can bed bugs stay dormant in an occupied home?
They don't need to: with someone to bite they feed every 3–7 days (Virginia Tech). No bites doesn't prove they're gone — some people don't react at all (CDC).
How long can bed bugs remain dormant in the cold?
Longest at about 13–15 °C (cool, not freezing). Below that, survival shortens, and long hard freezing kills them.
Does a cold, empty house kill dormant bed bugs?
Not quickly. Cool temperatures above freezing make them live longer, not shorter (Johnson 1941).
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.