Not sure if gerbil is sick or just weird

[munbunelle]

Hi! My name is Elle, I'm 20, and I own two gerbils, Sunny and Nyx. I purchased the boys from Petsmart (BIG mistake) midsummer of 2019 when they seemed to be about fully grown, so I'm guessing they're about 1-2 now. I had to have them both treated for tapeworms when I first got them (thanks Petsmart 🙄) and both now seem very active and healthy! My only issue is with their weight and behaviors.

Sunny is a very big boy, about 4.1 grams, and very shy. He's reluctant to come out of the bedding to check out what's up, but he's very gentle and never nibbles. He also doesn't try to run on the wheel very often, so I try to take him out of the cage for thirty or so minutes every day to let him run around on my bed and get some exercise in. He isn't lethargic in the slightest, and does take the wheel from Nyx sometimes, but doesn't seem to enjoy it quite as vigorously as Nyx does.

Nyx on the other hand is about 3.1 grams and hogs the wheel all day long. He's very prone to biting when picked up (I've been trying to discourage this with blowing sharp bursts of air on him so he associates biting with the unpleasant sensation) but very curious and likes to explore my hand when it's in the cage. I take him out to play on my desk- because he is VERY prone to peeing and pooping EVERYWHERE. He does rub his belly on every little corner and surface, so I know he likes marking territory, but my desk will be littered with little puddles of pee and poop within ten minutes! The urine seems to be of fine quality and his stools aren't runny, so I don't think he's sick, but his brother never shows any of this sort of behavior.

Is this Nyx showing his dominance or should I be worried about his health? Or is this completely normal and it's Sunny I should be worrying about?

[gerbilmom2018]

It sounds like just a difference in personalities to me. Both sound like normal gerbil behavior

[catnut]

is there room for two wheels? maybe Sunny would like to wheel more. It does some like dominance, how do they get along? also, blowing on gerbils can cause seizures in some so maybe just say NO in a firm but not too loud of voice and put him down if he bites.

[sandybadlands]

I agree that it's probably a personality thing. I had a pair that was exactly the same! (We still have the bigger boy, but his little brother died a couple months ago.) The littler one would constantly jump and beg to come out and play, even at dinnertime—so the big one would walk around eating all the food and also get less exercise, which contributed to their difference in size. Can't explain why lil bro thought our entire house was his toilet, though....