Round thing on my gerbil!

Question
I have three male gerbils in an aquarium. One is the father, and the other two are the sons. Today I noticed a little grayish thing growing on one of the boys by his hip. My mom touched it and said it felt hard. I thought it was a tick, but what do you think it is and is it bad, contagious etc.  

Answer
Hello,

Unfortunately i can not tell you what it is without him being examined. I think you need to take him to a vets to get him checked over! Is it seperate to the skin, or is it growing under the skin? Sometimes gerbils can get tumours, and the earlier they are treated the better! They tend to be more common in older gerbils but can occur at any age.

I hope this helps, and am sorry i can not tell you more about what it is!!
Thanks and feel free to ask again!!
Charlie.