Amphibians and Reptiles

Remember the last time you went swimming? If you tried holding your breath underwater, you probably weren't able to stay under for very long. Amphibians are animals that spend part of their life living in water and part of it living on land. They are vertebrates, which means that they have backbones. They are cold-blooded. This does not mean that their blood is cold. It means that their body temperature is controlled by their surroundings. For example, a frog can live through a cold winter by digging into the mud on the bottom of a lake. It doesn't freeze because its body adjusts to the cold temperature of the water.

Reptiles spend all of their life on land. A reptile is also a cold-blooded animal. It is a vertebrate. Snakes often warm themselves by laying on a rock in the sun. They may use the same rock for shade later in the day to cool themselves off.

Try it!

Take two sheets of art paper (white and black) and cut out two different snakes. Tape a thermometer to the underside, ”the belly” one snake at a time, and lay them on a shelf near a window or outside in the sun for 5 minutes. Record the temperature. Now find a cool place for your snake. Wait 5 minutes and record the temperature. Now repeat the process using the other snake. See which one becomes warmer. Try other locations with your thermometer to see how a cold-blooded animal is affected by its surroundings. Graph your information. Be careful that you don't break your thermometer ... we wouldn't want it to croak!