Why do hamsters eat each other

I had 3 male dwarf hamsters and today I found one of them dead and the ohter two eating it. I wondered why this had happened they had a big 3 tier cage lots of food and water and I cleaned the cage at least once a week to make sure they were clean.
Why would they then eat one ???

Hamsters should NOT be housed together under any circumstances. They are very territorial creatures. They are sold and housed together in many petstores because they are young. As they reach adolescence they will fight to the death for territory. They each need their own cage.

Here's a picture of my hamster, Zippy. I had him for 3 years before he died last year.

I don't know but that's really gross. Seriously. Google it.

EEEWWW!!!

It's normal. Male hamsters are territorial and, once they get old enough, fight each other to see who will win the territory. You really need to keep them in separate cages from now on! Eating the dead one is just a tidy way of keeping their nest clean. Mothers do it to their dead babies too. It would be yucky for humans but it's what makes sense in the hamster world.

Well, from now on you should keep them serparated because when your hamsters get older they will fight for there territory.
I hope you can get another Hamster to replace the one that had died