Food spoilage happens when the food we eat gets yucky and gross. This can happen because of bacteria, fungi or mold that grow on the food. Just like we need good air to breathe and water to drink, these tiny things also need food to grow and survive. Sometimes, they can find their way to our food and start munching away, which makes our food spoil.
When we leave our food out for too long, these tiny things can grow faster and cause our food to spoil even faster. This is why we need to put our food in the fridge, to stop the tiny things from growing and eating our food. The fridge is like a cooler box that helps to slow down the growth of the tiny things.
Spoiled food can make us sick and even cause us to have diarrhea or throw up. This is why we need to be careful and not eat old food or food that has been left out for too long. Always make sure to smell and look at your food before eating it, and if it smells bad, looks strange or has mold on it, it's best not to eat it.