In short
Adult bed bugs can go several months without a blood meal at normal room temperature, and longer in a cool, empty room; young nymphs survive for weeks rather than months. Warmth shortens it because the bugs burn energy faster. That is why leaving a flat empty for a few weeks, or bagging a sofa for a month, will not get rid of them.
In this guide
It is one of the first questions people ask once they have found bed bugs: if I move out for a while, or seal the mattress in plastic, will they just die? The honest answer is that they can last a surprisingly long time without feeding, and much longer than most people are prepared to wait.
The short version in numbers
Bed bugs feed on blood, usually every few days when someone is sleeping nearby. When there is nobody to feed on, they slow down and wait. How long they can wait depends on two things: their life stage and the temperature.
- Adults at ordinary room temperature commonly survive two to four months without a meal, and in a cool room they can last considerably longer.
- Nymphs, the young stages, have smaller reserves and generally survive weeks rather than months, but the older nymphs come close to adults.
- Eggs do not need food at all. They hatch in about one to two weeks at room temperature, and the newly hatched nymphs then need a meal before they can grow.
Figures in different studies vary widely because they were measured at different temperatures and humidities. What they all agree on is that a few weeks is not enough.
Why temperature matters so much
Bed bugs are cold-blooded. In a warm room their bodies work faster: they digest, move and use up their reserves more quickly, so they need to feed sooner and die sooner without food. In a cool room everything slows down and they can wait much longer.
That has two practical consequences in Manchester:
- An empty flat over winter is good for the bugs. With the heating off, an unoccupied flat or student house can keep bed bugs alive for months, waiting for the next tenant.
- A warm, occupied home never starves them. As long as someone is sleeping there, they have food.
Why starving them out does not work
Leaving the flat empty
Moving out for a fortnight, or even a couple of months, does not clear an infestation. The adults will still be alive when you come back, and any eggs will have hatched in the meantime. People who try this often find the problem is unchanged on their return, except that they have also carried bugs to wherever they stayed.
Sealing furniture in plastic
Wrapping a sofa or mattress in plastic sheeting for a few weeks will not kill the bugs inside, for the same reason. It also makes the furniture harder to treat properly later. A purpose-made mattress encasement is different: it is designed to be left on for at least a year, trapping any bugs inside until they die and stopping new ones from hiding in the seams.
Bagging clothes
Clothes sealed in a bag are a different matter, because you do not need to wait for the bugs to starve. Washing at 60°C and tumble drying on hot for at least 30 minutes kills every life stage. Freezing small items at -18°C for several days also works. Bagging is useful to keep treated items clean, not as a treatment on its own.
What this means for landlords and student houses
The long survival time is why bed bugs are such a problem in rented property. A house that had bed bugs at the end of one tenancy can still have them when the next tenants move in months later, even if it sat empty over the summer. That is unfair on the new tenants and usually lands on the landlord to fix.
The time between tenancies is actually the best moment to deal with a known problem, but by treating the empty house, not by waiting. An empty house is easier to prepare, and heat treatment works particularly well because there are no belongings to clear. Our page on student lets and landlords covers how whole-house treatment is usually planned.
What actually gets rid of them
Since waiting does not work, the options are the ones professionals use:
- Heat, which raises the room and its contents above the temperature bed bugs and their eggs can survive. One long visit deals with every life stage. Our heat treatment page explains how the day runs.
- A spray course, with residual insecticide in the seams and joints where bugs hide, repeated about two weeks later to catch the young bugs that hatch after the first visit.
- A combination of the two, often with steam on beds and sofas.
The NHS advises contacting a pest control service, because bed bugs are hard to get rid of yourself. If you are in Manchester, you can get a free Manchester bed bug treatment quote from a technician who covers your area, or use the cost calculator to see typical prices first.
A note on returning to a treated home
After a professional treatment you should move back in and keep sleeping in your own bed. That sounds counter-intuitive, but any surviving bugs will come out to feed, cross the treated surfaces and die, which is how a residual treatment is meant to work. Staying away gives survivors time to wait it out.