Are these snails mating? How big do ramshorn snails grow?

How big do ramshorn snails get? I got seven of them with a LFS java moss ball. They seem to be growing really fast and I'm curious if I may run out of space. Also, how do you sex a ramshorn? Can you sex them at all?
I found two unidentified pest snails on top of each other, at the water line, and in a gathering of tiny bubbles? Are they mating? One is smaller than the other. Also, what kind of snail are they and how big do they get?
I appreciate any feed back! Thank you!
Here are some rams horns, and the two unknown pest snails.

 

Ramshorns can reach about an inch. They're hermaphrodites, so both sexes. From the picture, it looks like the other snails are bladder snails that are mating. They stay pretty small. Maybe half inch?

 

The biggest one there is about 5/8". These ones in my frog tank are very well fed and the frogs eat most of the babies eliminating the competition. They don't grow nearly as big in my other tanks.

 

Okay..now I am kinda excited for them to get big. That's free tank cleaners on my part. Thus far, I only have 3.
With all the tanks I have, I should be able to handle the population pretty well.

 

The way snail populations work is they expand to consume all available food and will regulate at that level. The frog tank gets a few grams of food a week and the frogs miss a lot of it. If the frogs didn't eat the babies there would probably be an equal mass of much smaller snails.

In my fish tanks that only get a fraction of that food there are a lot fewer snails and they rarely get over 1/4". The guy I bought the original 50 from had thousands of pea sized snails in his goldfish tank which is what happens when there is lots of food and no predation.

 

New witness!! Are these mystery snails mating??