Oysters and other bivalves are nature's water filtration system. In fact, they are irreplaceable keystone species, whose primary ecosystem is to improve water quality and clarity by removing pollutants such as sediment and excess nitrogen. A single oyster can filter several dozen gallons of water a day!
Rabbits have excellent hearing! Their ears, which can grow up to 10 cm in length, can be rotated up to 270 degrees to detect the exact origin of a sound, which they can hear from up to 3 km away. These ears can revolve independently of each other!