In Slither.io, players have many different styles. Some Snakes are Passive while others are Aggressive.
The aggressive styled snake will take every opportunity possible to attack another snake and steal their mass, whether it be through coiling, boa constricting, trapping them at the edge, or even teaming up with other snakes (Of course, the aggressive snake will then kill its teammates...). Aggressive snakes are sometimes not very smart and easy to kill if you time it right. Aggressive snakes are also known to frequently speed. In addition, aggressive snakes are often the creators of Mass Rushes.
The passive snake is a peaceful snake that will only go after the small, miniature pellets generated by speeding snakes or by Slither.io server generation. The passive snake rarely attacks (See subtype of passive snakes, Self-Defensive).
A common subtype of the Passive snake is the "Self-Defensive" snake. The self-defensive is mostly passive... but if threatened, it will eliminate the threat, and then go back to its peaceful nature.
The scavenger snake will not attack and instead follow other snakes. When he sees the other snakes create a mass pool, he will swoop in and steal lots of mass before retreating. Scavenger snakes are often a STAGE, and after this they will most likely "evolve" into another type of snake.
The snakes will coil in one place until other snakes arrive. When a snake is in their reach, they will follow it and kill it. If they succeed they will return to the spot and wait for new victims.