Yes, can come in on plants or in water from lfs. Right color for apple snails but unsure of what they are for sure. I have ONE or TWO in my tanks to clean up...but not heaps...they can quickly become a pest that you don't want and even though they clean up...they do still generate their own waste which adds to your total waste...so maybe just keep a couple and either grow the others in another tank..they live in cold water too...or ditch them.....that would be what I would do anyway....
Shaz...PS The Bronco's have not made the finals...first time in like 19 years..day of mourning in our house