People can react very differently to bed bug bites.
By far the most common way the body reacts to bedbug bites (when and if it reacts) is by developing a large red rash or itchy blisters. They may swell up a little and look like larger mosquito bites.
Bits can be in a row but do not have to be. You will not be able to distinguish any “bite” i.e. as if the bedbug has taken a bite out of the skin. The bedbug does not actually bite, but sucks blood like a mosquito.
The most common places a bed bug bites are the arms and legs, but also the back and shoulders. However, this can vary depending on how you sleep. If you sleep a lot on your stomach, you are likely to get more bites on your back where the duvet is not against your skin.
If you have never been bitten by a bedbug before, the rash can last up to 14 days or so. Some people get a rash and itch for a very short time after the actual bite, while others have itching for a longer time. Many people do not react to bed bug bites at all, which can make it very difficult for them to detect infestations at an early stage.