Death of our Gerbil, Gerber

Question
My daughter called my in tears this morning, she found our gerbiil dead in his cage. We removed "Popcorn" the other gerbil immediately. Gerbers face was caved in. We do not know what could have happen. The two di not fight. We beleive there is a mouse in the house, but could it have killed him like that? Now that Popcorn is alone, do we need to get another gerbil? Your help would be greatly appreciated.

Answer
Dear Valerie,
thank you for your question.
I think it's very likely that Popcorn had started to eat Gerber. That's sounds gruesome, but it's natural behaviour - it's their instinct to eat a dead mouse to prevent any smell that would attract predators and it's a source of animal protein.
A wild mouse couldn't kill a gerbil, the gerbil is much more aggressive and bigger, they are known to kill smaller mouse species if they have the chance. It's possible that Gerber had some sort of organ failure or a birth defect that wasn't visible, but I'm just guessing of course.

Gerbils are very social, so you will need to get another friend for Popcorn. A young gerbil, between six and eight weeks old, will work best. Gerbil introductions take a long time and they may try your patience, often they don't get along right away. Here's some info on how to introduce gerbils:
http://www.das-maeuseasyl.de/doku.php/en/species/mongolian_jird#introducing_gerb...
and another site with great general info and a guide to the split tank method for introducing gerbils:
http://www.egerbil.com/splittank.html#split_tank_method
I hope I was of some help to you
Jennifer