pregnant cashmere

Question
I will explain you my story and can you please give me your opinion! :) I got 2 gerbils exactly 3 weeks ago from pets at home, a blonde one Taska, and black one Cashmere, there were 4 in the cage. she picked up Taska by the tail and said 'yep im pretty sure thats a girl, that means there all girls cause theyre kept in same sex cages'.  i bought them a run a few days ago and i dont notice anything in the cage but i put them in the run early evening for about an hour, over each evening i keep seeing Taska (the one actualy sexed) trying to mate Cashmere, her sister! but cashmer just runs away. Sometimes but not as often i see CAshmere do it to Taska and taska arches her back and they both jump apart and run away. 3 days ago i picked Cashmere up and she felt much heavier than Taska and heavier than she used to feel and much less slender, and today when i saw her hunched in her cage she looked really fat. she drinks alot more then Taska too but eats less so thats not why shes fat i dont think. Shes also more nervous about me but then she always has been. i saw her collecting up hay and bedding  and making a nest about a week ago but never seen Taska do that. Do you think shes pregnant if so how can she be because she was housed with sisters acording to the pet shop. i do not know how exactly old either of them are. if theyre both girls would taska still mount cashmere!? if Taska turns out to be male would she stil mount her even though shes already pregnant? What do you think - sorry for my huge story! Thank you! ps if i do find babies should i leave them both in the cage even if theyre both sisters? thank you!

Answer
Hi Elle,

I actually worked in Pets At Home for a year, and so can advise you well on this situation.

Firstly, the gerbils come in from the breeders to Pets At Home ready sexed. So all the staff at pets at home need to do is put them in their cages. Unfortunately, as they are so young they can be difficult to sex, and the store won't actually guarantee the sex. If you are unsure i really think you should take them back and ask for some one who is confident in sexing, and get them both re-checked again.

It is normal though for same sex gerbils to attempt 'mating'. This is a dominancy thing, and they do it to assert who is the dominant gerbil out of the two. It sounds as though Taska will be the dominant of the two.

I am not sure she is pregnant, as you wouldn't notice it until she is literally due to give birth, and the other Gerbil wouldn't be trying to mate still. Again if you are concerned explain this to some one at pets at home. Which particular store is it? Do they have a vets inside? If so you can ask them to get the vet to quickly check it over!!! Also, it is normal for all gerbils, whatever sex to make nests and collect bedding from around the cage!

If you do happen to find babies, then yes leave them alone and don't touch them. You will only stress the mother and this can put the babies in danger.

Let me know which store it is you use, and let me know what happens!! If you have any other questions or if i have missed something please do just ask!!

Thanks,
Charlie.