Beaver hides in beaver dams, also don't forget to go up to breathe! Also, keep close to the left side of the map when you are close to leveling up
The Beaver is a Brownish, "Fish" in Deeeep.io, Also called Squirrel by Brazilian Players and commonly mistaken as an Otter. It is a tier 7 animal and it's the equivalent to the Anglerfish. Their special ability is to hide in beaver dams (the pieces of wood with orange food below it floating on the water surface), becoming completely invisible and invulnerable in them. They can be deadly when grouped, however, the beaver does require oxygen to survive, which means it has to surface every now and then.
Beavers are the only creatures that are able to hide in beaver dams, and because of this they are a lot stronger near the water surface than many other animals. The beaver dams only appear on the water surface, so the beaver should stay at the surface to utilize their ability to the furthest extent.
Hiding as a beaver is incredibly easy when near a beaver dam, as one could just boost into a dam and be save. Hunting practically works the same way. Hide in the beaver dam for some time, and when an enemy comes near, boost out of your beaver dam and hit the opponent. If the animal is stronger than you, go back into your dam and repeat. Stronger animals will be likelier to camp at your dam, however, know that the beaver has the advantage, as they can regenerate and breathe in the dam, and occasionally hit the opponent without them being able to hit the beaver.
For a friendly strategy, try to find two or three beaver dams close to each other and camp at them. Smaller creatures will not go near to you because they can see you, and you can enjoy all the orange bits floating beneath your dams.
The best strategy for leveling up quick though would be using boosts out of water to fly and catch "Flappy's", this would create a "Flappy combo" that exponentially increases your experience points every time you catch another Flappy in one flight.
When leveling up, the best choice would be to choose Penguin, as this animal is able to 'evolve' into three other animals, all of which are considerably strong. If this is the case, when coming close to leveling up, swim towards the left part of the map, as penguins can only survive in the cold areas. NOTE: the beaver cannot survive in the Arctic, so be wary.