The Roach is a unique unit and is best thought as a mix between the Zergling and the Hydralisk. They can deal a decent amount of damage even though they need to get fairly close to their target. Roaches regenerate very quickly at a rate of 5 health per second while they are Burrowed but still recover health at the normal rate while above ground. It is a common tactic to Burrow a Roach before it is killed to allow it to recover. A few seconds later, the Roach will be fully healed allowing it to fight just as if it were a new unit.
This ability is available to several Zerg grounds units including the Roach. A burrowed unit will dig itself into the ground rendering it invisible and cannot be attacked unless a nearby detector unit can spot its location. The burrowed unit cannot attack any units, but it can see a very small distance. This ability is great for hiding your injured units to allow them to recover health or for spying at certain locations, such as expansion points or outside enemy bases to track enemy movement.
Inceases the movement speed of the Roach while it is above ground to 3 (Fast). The Roach moves at a decent pace and attacks from a short range, so this upgrade isn't terribly important. However, if you plan to attack with a large swarm of them, then consider researching it.
Tunneling Claws
Source: Roach Warren
Minerals: 150
Vespene Gas: 150
Research Time: 110
Requirements: Lair
This upgrade allows the Roach to move underground while it is Burrowed. The speed is a value of 1.4 (Slow) and the Glial Reconstitution Upgrade does not increase this speed. Very useful for moving Roaches after they all Burrowed in an enemy base to make a surprise attack from another weaker side of the base. Usually the enemy will withdraw all of their forces to where the Roaches Burrowed leaving other places with little defense. Another tactic is to sneak them behind the enemies resources then take out all the harvesters. This upgrade will also increase the health regeneration rate of the Roach while it is Burrowed to 10 Health per second.
