Bacteria live almost everywhere on earth, even within and outside animals, including insects and ourselves. Some bacteria help us digest our food, but others do harm and cause infections and illness. If we are injured, bacteria from the outside can enter our bodies through our wounds. The body will then fight against the incoming bacteria and this fight affects our own, useful bacteria in two ways. First, the fight harms both the incoming bacteria and our own helpful bacteria. Second, because the incoming bacteria may also be bad for the useful bacteria, our own bacteria might fight against the incoming ones. To do so, they use special molecules to talk to each other—a little bit like we use words. We studied the conversation of bacteria of the bedbug because it is an animal that is wounded very often. We wanted to understand how bacterial conversation changes when new bacteria enter the animal’s body. We found that females had different species of bacteria before they were wounded compared with after they were wounded. We also found that the bacteria communicated differently after the females were wounded. Our study helps people to understand how an animal’s response to wounds and the communication of the bacteria in that animal work together.