Test Room 01 is the third room of Fredbear and Friends: Left to Rot. It is a sublocation of Fredbear's Family Diner. It is unlocked immediately after beating Storage and the active animatronics are Nightmare Mousiki and Rodger.
Test Room 01 is highly reminiscent of the child's bedroom from FNaF 4. The walls are covered with pale blue wallpaper and glow-in-the-dark spaceships stickers, and glow-in-the-dark stars hang from the ceiling. There are two white wooden doors and a vent which is found behind the player.
The player must click and hold on the vent behind them to raise it in order to escape the room. While doing this Nightmare Mousiki will attempt to enter the room through one of the two doors. There is a very faint sound cue announcing this, at which point the player must turn around and press space to flash him and drive him off. Failing to do so in time will cause Mousiki to jumpscare the player, resulting in a game over. The player must also keep the toy mouse wound up in order to repel Rodger, which is done by clicking and holding on the toy. The toy will slowly wind down, and the screen will flickering once it is about to run out. Letting the toy wind down completely will cause Rodger to jumpscare the player, resulting in a game over.
Once the player has lifted the vent enough they will automatically crawl through and exit the other side. The player will see a door labeled EXIT, but will be attack and knocked out by Suit once they click on the door. This is scripted and does not result in a game over. The player will then be given the next of the Training Tapes and will move on to Test Room 02.
At the beginning of the Test Room 01 Phone Guy will give the following information:
"Alright, now we couldn't really figure out what was in this room, but there should be an exit connected to the room. Once you go through the exit..." (note that Phone Guy fades to static before he can finish)
- Test Room 01 is the only room to be based on a location from the mainline FNaF series.
- Phone Guy losing connection while the player is in Test Room 01 is presumably because the player is now underground.
- As Phone Guy comments that the contents of Test Room 01 were not previously known, it can be insinuated that Test Room 01 is either a new addition to the underground testing facilities, or has been altered in some way by William Afton.