I don't think they would like to have a friend but will tolerate one of equal size? You can keep multiples in a tank with in reason. The rule of thumb is one adult per 5 gallon of tank space if I remember correctly (i don't remember if sexes make a difference or not). I had 1 male with two females in a 20 gallon tank and they all did just fine. Just make sure you have plenty of hides and plenty of food. Having 1 per tank I think makes life a little eaiser because you can monitor feeding, bath room habits and other things much more closely. I am more of a tarantula person so scorpion people will be able to help out much more...