American foulbrood is a serious bacterial disease that affects honeybee larvae. It is caused by the bacterium Paenibacillus larvae, which infects the brood and can lead to the death of entire colonies. Infected larvae turn dark and become a sticky, foul-smelling mass, making early detection crucial for beekeepers. The disease spreads through contaminated equipment, honey, and bees. Once a colony is infected, it can be challenging to control, often requiring the destruction of the affected hive. Preventative measures, such as maintaining good hygiene and monitoring bee health, are essential for beekeepers to protect their colonies from American foulbrood.