Bed bugs are tiny bloodsucking insects that are about the size of the width of a credit card.
They usually live in tiny cracks and crevices in the bedroom, and creep out at night to feed.
The bugs aren’t necessarily dangerous, but they can be very annoying, and some people may have a bad reaction to their bites.
Itching or swelling could be one of the first warning signs that you’ve been bitten by a bed bug.
Although some people may find themselves itching the day after being bitten, the actual bites may not become visibly obvious for a number of days, said pest control firm Orkin.
Some people have no reaction to the bites at all, and they never become visible.
One of the biggest signs of a bed bug infestation is having a series of bites in a line across the skin, it said.
“Unlike those of other insects, bed bug bites may sometimes appear in tight lines of multiple, small, red marks where multiple bed bugs have fed along an exposed area,” said Orkin.
“Bed bug bites can cause itchiness. Initially, a victim may detect a slight burning sensation.
“The burning area then develops red bumps, known as papules or wheals [rash].
“In extreme cases, bites may swell dramatically or turn into blister-like skin inflammations.
“Many people do not react at all to the bite of a bed bug — many bites leave no mark and go completely unnoticed.”
Most bites are found on parts of the body that are exposed during the night – the hands, neck, face or shoulders.
If you’re unsure whether you’ve been bitten by a bed bug, check for signs of blood on your bedsheets.
The bugs can also leave behind faeces and skin casts before crawling back into their hiding space.
The average bed bug is about the size of an apple seed, with a flat, oval-shaped body, said the NHS.
They can move up to 20 feet from their hiding places to feed. The bugs can spend between three and 12 minutes feeding.
If you think you have a bed bug infestation, it’s best to speak to a professional as they can be difficult to get rid of.
You could also help to remove bed bugs by washing infested clothes and bed linen at a high temperature for 30 minutes.
Use a vacuum cleaner to suck up any bugs visible to the eye, and then dispose of the contents of the vacuum cleaner in a sealed, separate bag.