I would suggest keeping them in another room if possible. Not that it will hurt anything or make them more aggressive, but simply because of your snakes feeding response. It is recommended to prescent the room to build a better feeding response from your animals and with rats in the room you can't properly prescent. I have around 90 ball pythons and with prescenting I will have a 90-95% success rate on feeding day. I think if my animals could smell rats 24/7 this % would drop greatly.
Many rats in my snake room, weird, they eat almost every time, and they are pre-scented 24/7...lol
I can even pre-scent my hands, and grab any snake I want, with no bites, funny how that works.....