I have just noticed all these snails pop up today. How on earth did they get there. Iv added no new plants, decor or fish recently and the last I heard snails don't just fly. There's about 20 of them that I can easily spot. There prob only about 2mm max. I cleaned my pump 2 days ago and did a 40% water change and didn't notice anything then and did nothing other than the norm. I do have one nitrite zebra snail in there but I thought they could only breed in brackish water. And he's been on his own for years. I do have 2 clown loaches and 2 Pakistani yoyo loaches so would of thought they would of gobbled them right up. Any help or advice would be greatly appreciated. I don't really want to use chemicals to get rid of them as I'm wary of using anything with my scaleless fish Iv attached a pic in the hope someone may be able to tell me what they are and if there a pest or not. Thanks folks.