Emergency!

[GeckoX]

GML,   One of my baby gerbils is not eating and seems to be *extremely* weak compared to the other pups. It seems too weak to even open its eyes. It was born on the 26th of June along with the other babies...so I dont know what could be happening.   One observation I made was that the pup was constantly licking the glass of the tank for hours at a time...I figured it might have been looking for food/water so I tried giving it some, but it didn't accept it. I looked for toxins on the glass but there's no residue of anything that might be harming it...   PLEASE HELP, Jason