I have seen all kinds of snakes in my yard (and inside the lanai), most of them harmless. However, the cottonmouths scare me! I think I will feed the pond from a distance and NEVER go near it after dark or during dusk hours! Not sure how aggressive these snakes are. Obviously any snake will be aggressive when cornered, but I will eventually need to service my pond's filter and thin out the hyacinths. I think I will put off that chore as long as I can!!!