Domestic cats do not eat bed bugs as a matter of course. Although a cat might nibble and play with one from time to time because cats are instinctively interested in small moving objects. You can stop there if you like but I will discuss bed bugs some more.
Bed bugs as a cat prey item
Bed bugs are not a domestic cat prey item. Although, they are insects and insects are, in general, creatures that a domestic cat likes to eat. However, adult bed bugs are about 4 to 5 mm in length. They’re too small to be of interest to a domestic cat as a meal. I suppose that if a domestic cat saw one they might be interested in playing and nibbling at it but you can’t rely on a domestic cat to eradicate your bed bug infestation by attacking and eating them!
The question in the title is interesting because it is not the sort of question you would think would be asked. Why is the question being asked? Perhaps people who have bed bugs are finding it difficult to get rid of them and are considering adopting a cat to achieve what they are having difficulty in achieving. It won’t work in my opinion.
Spreading bed bugs
Domestic cats and dogs are believed not to be a factor in the transmission of bed bugs, i.e. their spread. Infestations are caused by the insect being transported from one area of infestation to another. This might occur if a person has visited a home where they are present. The insect climbs onto that person and they bring it home. As I understand it, this is the kind of way you end up with a bed bug infestation in your home.
Perhaps the classic way you end up with bed bugs in your bed is because when travelling you bring them back in your luggage and you place your suitcase on your bed to unpack it. That’s when they emerge and occupy your bed. If you’ve visited a place where there might be an infestation, place your suitcase in the bath first and unpack it there 🙂 .
Bed bugs on cats
Although bed bugs feed on the blood of humans they might feed on a domestic cat but they do not stay there like cat fleas. In other words they may opportunistically feed on pets but it is not a stable or habitual state of affairs.