I live in London and had bedbugs in my apartment 2 years ago. I knew what to watch for (colinear musquito bites), so got rid of them at the first sign. No idea

I live in London and had bedbugs in my apartment 2 years ago. I knew what to watch for (colinear musquito bites), so got rid of them at the first sign. No idea where they came from, though. But the building is old and they might have crawled from a neighbour's bedroom.