Rat

Rats are common rodents, able to survive almost everywhere.

Tactics
Rats, one of the easiest enemies in the games are most commonly found on the ground or swimming in water. Simply shoot them with your Dual Pistols, and jump backwards if you're on solid ground and they get too close. They are capable of biting Lara which causes little damage but can cause her health bar to drop significantly if they continuously bite her.

Tomb Raider

 * Palace Midas
 * The Cistern
 * Tomb of Tihocan

Tomb Raider II

 * Venice
 * Bartoli's Hideout
 * Opera House

Tomb Raider II: The Golden Mask

 * Fool's Gold
 * Furnace of the Gods

Tomb Raider III

 * Thames Wharf
 * Aldwych

Tomb Raider: The Last Revelation
Appears as animating object only in one of the Cairo levels. Not an enemy

Tomb Raider (2013)
They appear as animals that can be hunted throughout various locations on Yamatai like in The Last Revelation they are not enemies.

Rise of the Tomb Raider
They appear as animals that can be hunted throughout various locations, and are neutral.