Virus

Scattered around the map you can find green balls with spiked edges called viruses. When a cell of 133 mass or greater consumes a virus, they will split into many pieces, making them easy targets for other cells. Players not large enough to consume a virus will pass through it harmlessly, making it a safe haven for small cells. The virus will also hide a small cell inside of it, so small cells can use viruses to hide from large cells or plot a sneak attack, though, when a player is larger than a cell and very near to 133 mass, he will not hide behind it, but rather be seen in front of it. Once a player has 16 independent cells, running into a virus with a cell of over 132 mass will result in the cell disappearing without effect.

A new virus can be created by a cell by ejecting 7 blobs at a maximum by using the W function. When the virus is given the seventh blob, it will eject another virus in the direction the player is moving. This mechanic is often used to attack larger cells who would otherwise be impossible to consume. Keep in mind that when you are in range to give mass to a virus, you are also in range for the ejected virus. Ejecting viruses at other cells has considerable risk of counterattack.

While the exact number is unknown, there is an upper and lower limit to the number of viruses that can exist on the map. When the lower limit is reached, a virus will randomly spawn on the map (not on top of a cell). When the upper limit is reached, all mass ejected towards viruses will pass through them so that cells cannot create more viruses.