Hey boy you got a purdy mouth now lets just you drop them pants. Gettem off, panties too.Looks like a Dr just b4 he is going to check .......oh wait you mean that invert........
lol
That first pic is most likely a Stomatella snail. They will reach high numbers depending on how much food is available to them and as you found out, they move pretty fast. I sell off about a dozen every few months.
And I'm glad to see someone wearing PPE with the gloves.