Kids love learning about how birds build their nests, and you can show them how to help the birds find materials for the building process. In the springtime, when birds begin to return to your area, help your child gather many different ribbons, string, scraps of fabric and other materials that a bird might use in building a nest. Make sure to use bright and colorful scraps. Talk about which scraps they think birds would be most interested in and why. Then punch holes in a piece of cardboard and let your child thread the scraps through each of the holes. You can hang the cardboard from a tree and see which pieces the birds used to build their nests. Don't forget to look out for nearby nests using the materials you set out for them.
On your next trip to the beach, bring along some black construction paper, a magnifying glass and some vinegar. Children can spill some sand on the black paper and examine it with a magnifying glass. They may be surprised to discover that sand is made of different types of materials, which are easily visible under the glass. You can then show them how to spill a small amount of vinegar over the sand, and watch it bubble. Explain that the parts of the sand that are bubbling were once alive, and discuss the different possibilities of what might have been alive that is now sand, such as seashells, fish bones and coral.
Many preschoolers love bathtime, and one reason they love it is because it's one giant science project for them. Give them additional time learning about one of the properties of water with this floating and sinking activity. Fill a large basin with water and collect several waterproof objects from around the house or yard, such as pebbles, a pine cone, a flower, a piece of paper, an action figure and a grape. Kids should make two piles, one with all of the objects they think will float and one with the objects they think will sink. Then let them test out their hypothesis.