Mold is a fuzzy fungus that grows on damp food. Tiny spores (seed-like particles) float through the air and land on surfaces like bread. When you add water and seal bread in a warm spot, those spores find the right conditions and grow into visible fuzzy patches within days.

Warmth is one key condition that lets a simple fungus like mold get started. Tiny spores land on a surface and begin growing when conditions are right. Rub a cotton swab of household dust across a piece of bread, add a few drops of water, and seal it in a plastic bag. Place one bag in a warm spot and another in the cold, then check daily to see where fuzzy patches appear first.

Moisture is water on a surface. Mold needs that water to grow. You add a few drops of water to bread and seal it in a bag. The water stays on the bread's surface. Within a few days, fuzzy patches of mold appear.

Mold is a simple fungus that feeds on food sources like bread. Tiny spores land on the surface and start growing when moisture and warmth are present. Rub a cotton swab of household dust across a piece of bread, add a few drops of water, and seal it in a plastic bag. Place it in a warm spot and check it every day — within a few days, fuzzy patches appear.

Spores are tiny seed-like particles that start growing when conditions are right. In this experiment, you collect dust on a cotton swab and rub it on bread. You add water and wait for mold to appear.