Autoinducers are small signaling molecules used by bacteria to communicate with one another. They play a crucial role in a process called quorum sensing, which allows bacteria to coordinate their behavior based on their population density. When the concentration of autoinducers reaches a certain threshold, it triggers changes in gene expression, enabling bacteria to act collectively. Different species of bacteria produce various types of autoinducers, which can influence behaviors such as biofilm formation, virulence, and bioluminescence. This communication system helps bacteria adapt to their environment and can enhance their survival and efficiency in diverse ecological niches.