An amoeba is a tiny, single-celled organism that lives in water, soil, and even inside other living things. You can't see an amoeba without a microscope, but under magnification, it looks like a blob of jelly that constantly changes shape as it moves and eats.

What makes amoebas fascinating is how they get around and catch food. They extend parts of their body called pseudopods (which means “false feet”) to push themselves forward, like stretching out fingers made of living goo. When an amoeba finds something to eat, like a bacterium, it wraps its pseudopods around the food and absorbs it into its body.

Scientists study amoebas to understand basic life processes, since these simple creatures can eat, move, reproduce, and respond to their environment using just one cell. Most amoebas are harmless, living peacefully in ponds and puddles. A few species can make people sick, which is why you shouldn't drink water from streams or lakes without treating it first.

When someone describes something as amoeba-like, they mean it's constantly shifting and hard to pin down.