Check on Malaysian Trumpet Snails.
They are little they will get up to over half inch.
they are a hassle sometimes, on the benefit side they move substrate around, (you are probably over feeding you can do more cleaning on your substrate,) and if there is a poor water quality in your tank they will all rush (not too fast because they are a snail - lol) up the side of the tank towards the top.
They can be like an alarm. When my big Blue Mystery Snail died in my shrimp tank, I didn't notice but the next day they snails were everywhere heading to the top. Because its dead body was fouling up the water. I found the problem and took it out and did big
pwc.