Reptiles - Jan 2010

I began the year with my favorite topic - Reptiles. I usually begin class with a book and this week I used CAN SNAKES CRAWL BACKWARDS. I began with talking about animal classifications.

Vertebrates - have a skeleton
Invertebrates - no skeleton

The 5 main classes of vertebrates are Mammals, Birds, Reptiles, Amphibians and Fish.
There are 5 orders of groups of reptiles living on earth today:

Tuataras, Snakes, Lizards, Crocodilians, Turtles

There are many types of extinct reptiles.

I then went over the characteristics that make a reptile a reptile:

1. Scales - I asked the kids to show me there scales. They of course responded that they had no scales and I pointed to there fingernails and hair. They are made of keratin which is the same material reptile scales are made of. Why are the scales so important? I explained that if I made a sandwich for their lunch early in the morning and left it laying in the desk all day that my lunch it would be dry and stale and not very good. I asked what I should do with the sandwich to make it better for lunch and most kids know you should put it in a zip lock. Think of scales like a zip lock. They keep reptiles from drying up and allows them to live in saltwater and hot, dry desserts that the amphibians with no scales can't live in. The scales also protect their bellies. I asked the kids if they would like to crawl through the park on their bellies in a bathing suit. If they had scales they could.

You can cut the end off of a pillow case and put it over a child and let them lay down and try to shed their old scales off. Remind them that if they were a snake they'd have no arms to help with. Real snakes don't just crawl out of their skin but they peel it off like a banana skin.



2. Breath with lungs - Reptiles do not have gills so, sharks are not reptiles even though they have scales.

3. Body Temp - Reptiles are cold blooded, we are mammals and are warm blooded. We can make heat to maintain a steady temp. If we go out to play in the snow we don't die. Reptiles do not have ice in there blood but they can't make heat (except a few pythons when protecting eggs). If a lizard goes out in the snow it will die. Even if you put a coat, hat and gloves on it. That's why they hibernate in winter or live in warm places.

4. Reptiles lay eggs with shells.

I then gave everyone a toy reptile, amphibian, fish and eel. I said crocodilian and everyone with a croc or alligator put it in line,snakes, turtles and lizards. We talked about why the salamander wasn't a reptile (no scales and only 4 toes on the front legs). You could do this with pictures too.

I have 2 live snakes we looked at, ask around the school many kids have pet snakes or lizards they'd love to bring in to share. Make sure it's friendly before allowing anyone to touch it.

Our project for the week was making a snake scarf. We made a nonvenomous constrictor. I had explained when holding the snake that I never hold one around my neck because when a constrictor gets scared it could squeeze. The scarf we're making is ok for the neck. I cut the snakes out of fleece ( I got about 7 snakes per yard). You could get more by making them little shorter and skinnier. We then glued on eyes cut out of white felt, forked tongues of red felt and we glued in elliptical pupils of black felt. Our pythons are nocturnal and need eyes to open wide at night. My older students added the nostrils and heat seeking pits with a black sharpy.