Swamps or maybe those in the desert. In swamps, the soil is too loose for animals to burrow without it caving in. In deserts, since the climate "rising" its getting to hot and dry for animals to burrow without the sand caving in when an animal walks above it.
Just saying it says 8 points ya little baka
Check out this website http://science.jrank.org/pages/3421/Hummingbirds-Biology-hummingbirds.html
Do you have the solutions you want me to compare and contrast? :)
