At the end of last summer we made a largish wildlife pond: We're Making a Wildlife Pond It's doing well in it's early months but we have dozens and dozens of large (3-4cm) pond snails. They've just appeared. A friend gave me some plants and I noticed a few, very few tiny pond snails when I planted the plants but the ones I'm talking about are big and we don't really know where they came from. If there were snail eggs lurking on the pond plants or came in on birds legs I don't think they would be this big now. A nearby ditch perhaps? My question is, can you have too many? Should I be thinking of taking action....moving them to a new location or what? I don't want them killing all my new plants!