Infested troopers can attack from inside the infested bunker, and can enter or leave by player command, whether the bunker is rooted or not. If the infested bunker is uprooted, it has a "claw" attack.
When an infested bunker is produced, it includes 4 infested troopers within it. Every 30 seconds the bunker produces a single infested trooper. If it isn't full, the infested trooper is produced within the bunker and remains inside unless ordered out. If there aren't enough slots to hold all the infested troopers, new ones emerge outside and follow the psi emitter. They have a timed life of only 30 seconds once they leave the bunker, however.
Infested Bunkers regenerate life and automatically spawn Infested Troopers while rooted. Infested Troopers fight from inside the Infested Bunker and are deployed onto the battlefield if no slots are currently open.
Infested troopers that leave the infested bunker have a lifespan of 30 seconds.
24 (with Engorged Bunkers) With Lord of the Horde:
Root: Roots the structure at a target location (on creep), allowing it to once again produce units, research upgrades, and use abilities. Uproot: Uproots the structure, allowing it to move about freely. May not produce units, research upgrades, or use abilities until it is rooted.
The infested bunker was going to be a producible campaign unit for Heart of the Swarm, it would have spawned by emerging from underneath a terranbunker, warping the metal into itself, gaining a back-mounted cannon in the process. The unit was put into storage before being revived for Co-op Missions.