Adam & Eve, originally, had all their needs provided for until the snake (embodiment of the Evil Inclination, an outside force) caused them to Sin (through Eve). The snake was the second most important creature after Adam. He actually had legs and walked upright which is a sign of dominance and importance. His punishment was that he would now lose his legs and crawl on his belly. So displeased was G-d with him that he made sure the snake's food would be plentiful so that He would have no need to ever again deal with him (directly). Remember, the snake slandered G-d, His Creator--just about the greatest sin one can do in this world! Perhaps, this is where the statement, "the bigger (greater) they are, the harder (lower) they fall," came from.
**Eve made from Adam
first sin causes them to fall
men now fend alone**