How does a pufferfish inflate?

A pufferfish inflates by rapidly taking in water (or air) into its elastic stomach, which can expand significantly. When threatened, the fish swallows large amounts of water, causing its body to balloon and become much larger than its normal size. This inflation makes it more difficult for predators to eat and can also reveal spines that deter attackers. The ability to inflate serves as a defense mechanism against predation.