I don't think gerbils can get neutered; if they can, a vet would do the trick. A simpler plan would be separating the males and females so your poor gerbil doesn't get drowsy.
Male gerbils can be neutered, but it is not recomended. Female gerbils should not be spayed. In general male gerbils should not be neutered unless there is a good reason for it.
Yes,in fact they do. Either another gerbil or a person or thing they just do not like. If you have this problem,I suggest you return your gerbil immediantly or get him/her neutered.
Gerbils are capable of breeding very quickly, with fairly large litters which have fairly high survival rates. They must be introduced carefully, by allowing them to acclimatise to each other while they are separate. I would not recommend housing gerbils of opposite genders together, unless the male is neutered- and only young animals should be neutered.
There is no such thing as a "neutered cow." You can get a neutered bull, which is called a steer, or a spayed heifer, but never a "neutered cow."
This is easy. You need to look for its testicles. If it has them it is not neutered. If it does not it is neutered.
Other gerbils.
Gerbils are an animal and can not be "invented".
no gerbils are not originally from the UK but instead from the deserts of Asia. But you can still buy gerbils in the UK
Yes, mice are smaller than gerbils, but I think gerbils are the right size.
They don't need to be neutered
Yes, e.g Mongolian Gerbils.
They do have seizures (this is common in young gerbils)