Materials Needed:
1. Little Plastic Animals - at party supply places each will cost you around $0.50. You can also get them at craft stores which may cost you more.
2. Glue gun and extra glue sticks. Glue guns vary in price according to how fancy-pants they are. A pack of 30 (wood/plastic/glass type) glue sticks cost around $2.50
3. Some type of glass container/jar/vase - You can buy some as cheap as $1.
4. Vase filler pebbles - Anywhere from $3-6. You can also use sand.
5. Little pens, pencils that have become short, golf pencils. I bought the little pens at a party store (12 pack) for about $3.
Directions:
1. Fill the vase/jar with pebbles.
2. Grab glue gun (make sure it is heated). Glue the animals onto the little pens.
3. Wait at least 30 seconds for glue to dry.
4. Put some more glue on to secure the crap out of the pen.
5. Stick pens into your ecosystem. Make sure you have enough pebbles to cover the whole pen so it doesn't look tacky.
Adapt the idea to make it with your favorite animals. (FYI I wanted bad-a** safari animals but couldn't find any)
Another totally awesome idea would be to make some with Lego characters.
Also add trees and plants for extra points.
Here is a woodland creature one I did because beavers are cool.
