Animal waste and rotting food are bad to have around a kitchen. This is where the infamous bacteria E. coli and salmonella can be picked up. E. coli is mostly found in animal and human waste, and can be transferred to the water system, then onto people's hands, then onto food. Luckily, there isn't much danger of E. coli coming out when you turn on a tap. Using antibacterial cleaners and washing your hands regularly when cooking are said to prevent food poisoning.