The beavers are really enjoying themselves, gnawing at a tree trunk and building their dam. But suddenly a grey water rat flashes by, and there's another one back there ... The aim of this funny card game is to get as few cards as possible with the nasty water rats.

Each player has four cards face down on the table, only two of which he may look at at the beginning. From then on, there are only a few ways to find out what is shown on the front. Is it a dozing beaver with a low numerical value or a nasty water rat with a high value that makes the beavers bother? Because one should get rid of these little grey rodents as quickly as possible. Special cards allow you to view one or the other card during the game or to send a bad card to your fellow players.

At the end of a game round, all cards are revealed and the numerical values of the cards are noted. Who has the least points after several rounds, wins this funny card game and deserves to recover the rest of the day with his beaver friends from the squabbles with the water rats.