Cats act oddly afer coming indoors

Question
Hello Mick,

 This might sound like an odd question. My 2 cats love each other, they are both spayed females and get along perfectly indoors. The weird thing is after they come back from playing outside in their pen, the older one hisses and growls loudly at the little one. And she does this for a good day or 2, then she's all good again. Is this odd or what? please help me in figuring out whats going on... thanks a bunch!!

Answer
Hi, since she is the older female she is the more dominant and she is just warning the little one that this is her teritory.To end this what you should do is when they are together you must treat the older one with more respect like feeding her first or peting her first talking to her in a soft tone.This does not mean that the other one should be not payed attention too when you see that the older cat leaves then pay much attention to the younger cat so she feels important to.THANKS!!!!