Make snot to demonstrate how the body filters the air we breathe. Mix 1/8 cup of Borax with 2 cups of warm water. In another container mix 2 tsp. of glue gel with 3 tsp. of water. Add a few drops of yellow and green food coloring. Pour both containers into a zip-top bag and seal. Squish the bag to mix. A slimy concoction will form that resembles snot. Take the mixture out of the bag and play with it for a while, noting its characteristics. Lay it on a table or flat surface and blow dust or fine pencil shavings across the top to see the filtering effects of snot.
Teach students about an earthworm and its habitat by making a worm farm. Cut off the top portion of a 2-L plastic bottle, poke air holes near the bottle cap and set aside. Make a few small drainage holes in the bottom part of the bottle and set in a shallow container. Next, mix shredded newspaper, 2 cups of soil and 1 cup of water until most of the moisture has absorbed and the mixture is damp. Put this inside the bottle. Add six to 12 earthworms. Tape the top back on the bottle and place in a dark room. After a few days, observe the tunnels the worms have made in their habitat. Continue to observe them over the next several days, feeding them small pieces of grass, fruit and vegetables and keeping the soil moist.
Heat 4 oz. of milk on the stovetop until lumps form. Pour off any extra liquid. Place curdled milk into a jar and add 1 tsp. of vinegar. Let this sit for at least an hour. The mixture should transform into a rubbery blob. Pour off remaining liquid. Shape the rubbery creation into a ball or other shape and lay on paper towels to dry. After several hours the shape should be completely dry and hardened. When the vinegar is added to milk, milk separates into liquid and a solid made up of a protein called casein. The casein is what causes the milk mixture to harden into a plastic-like substance.
To determine which surfaces in the classroom contain the most germs, grow a germ garden. Wipe a piece of white bread over each surface to be tested while wearing rubber gloves. Place each slice of bread in a zip-top bag and label it according to the surface. Sprinkle 1 tsp. of water into each bag and seal. Place the bags in a sunny location and observe. After a few days, all the bread will mold. However, some mold will grow quicker and some will look more disgusting due to the different kinds of germs collected from each surface. Record your observations in a notebook each day.