Bat

From Resident Evil Wiki

[edit] Infected Bat

Vampire Bats infected with the t-virus, seen inside the cathedral in Umbrella's Management Training Facility. These bats were created through exposure to the t-virus through the leak caused by the newly revived James Marcus.

There were also infected bats on Rockfort Island during the viral outbreak, but these showed no sign of increased size and could be deterred by light or usually avoided by walking instead of running around them.

If you are playing and you encounter bats, all you have to do is equip your lighter and you'll be fine.

[edit] Giant Bat

Also see: Infected Bat

Although typically the only sign of infection was increased aggression, one bat in particular mutated to an enormous size. The mutation took a heavy toll on its body, causing multiple muscle tears in its enormous wingspan. This infected bat also had the ability to spawn multiple offspring at an alarming rate. The creature was destroyed by Rebecca Chambers and Billy Coen.

[edit] Un-Infected Bat

Bats were also seen by Leon S. Kennedy in his exploration of the Salazar Castle. In Resident Evil 5, Chris and Sheva can kill optional bats for gold. Bats in RE5 can drop grenades which is rare.