I was feeding my ball python today. She's almost 7 months old and eats well. She ate two small mice today. But I noticed something as she was swallowing her mice, there was a small dark gray dot on the rim of the bottom of her mouth. About dead center.
I'm sorry for such terrible quality. It's hard to hold a camera in my mouth...

I didn't have the proper tools to open her mouth but they say you can use a business card of some sort for smaller snakes. But as you can see there's a small dark dot.

Is this a sign of mouth rot? I'm really concerned. Vets cost so much just for you to show up... and I really don't like the thought of her having this.

She lives in a 20 g tank with two hiding spots both on the hot zone and cool zone. Here hot zone is about 85 degrees inside of her tree, but if she climbs to the top it's 110 degrees. In the cool zone it's a 75 degree temperature. I keep the heat lamp on all night, which is an infrared nocturnal viewing bulb that only emits a dim purple/red light at night. She gets fresh water every week. I try to change it twice a week. She has cypress as her bedding and she just got out of shed. The humidity is at a 42% right now but I've been told that you can keep it low when they're not in shed. I think my dad still mists it every morning, though, so she's aware that there's water. I feed her live, small mice. She last ate today, two small mice. And she also ate two Sunday, I believe. I lost my record keeping notebook. Maybe I should cut down a feeding a bit... I'll wait a week to see if she poops and all.

But is this a sign of mouth rot? Jeez, it's scary. I love my snake and I want the best for her.

Thanks.