Thank you! Ah, there's a whole evolutionary chain of another electric mouse; pichu, pikachu and raichu, Pichu is the tiniest of them and Raichu is the biggest. You'll also run into rats soon -- but those and some others counts as Mouse pokemon species here, and there will be bugs and more birds on the next route too. So you'll find the first bugs as soon as you get to the route, and then there are forest full of them and other species.