Spurs

What are they at the end towards their tails?

Don't under stand your question.
Spurs are I believe the remains of hind legs in Boids(pythons, boas, annacondas). Not sure what other snakes have them. Both male and females have them but the male's are usually bigger. The male uses them to "tickle" and stimulate the female into breeding. They are on both sides of the vent.
Hope this helps

Just remember that spur size is not a reliable way to sex your snake...only probing or popping by an experienced person or vet is.

Heres a good picture of one
http://upload.wikimedia.org/wikipedi...Anal_spurs.jpg
taken from: http://en.wikipedia.org/wiki/Image:Anal_spurs.jpg