As we looked at before, the cell is an amazing thing! It is miniscule yet it is the foundational workhorse for all living things. There is another type of cell called the paramecium. This is a protozoa (a complete cell) that looks like a slipper. The paramecium is a hairy little guy, these hairs are called cilia. The cilia are like the paramecium's oars. They help it move. The cilia also help the paramecium eat. When food is found near, the cilia close around it and begin to absorb it.
Paramecium are found in almost all bodies of fresh water. Yet, some protozoans are dangerous to humans because they carry disease. Malaria is a disease that is passed on to humans from protozoans carried by a mosquito. Yet, most protozoans are beneficial because they eat algae!
Can you believe that these tiny creatures were discovered by an amateur scientist who studied and experimented in his spare time? Anton van Leeuwenhoek liked to study nature and had special lenses made so he could see things close up. One day he held these lenses up to a drop of water. He was shocked to see tiny little creatures swimming in it!