To become a mouse in Crab Lab , you usually need to find the mouse holes and use a shrink method to enter them. The clues from those holes combine into a code that unlocks the related morph room, and that’s where the mouse-related access appears.

What to do

  1. Look for the mouse holes in the map.
  2. Shrink your character using the shrink machine or a shrink watch.
  3. Enter each mouse hole and collect the clue from it.
  4. Put the clues together to form the room code.
  5. Use the code to enter the secret room and access the morph.

Important detail

The mouse holes are reported in Sector 2, Storage, Escape Pod, and Reactor rooms, and each one gives part of the code. A separate wiki page also notes there used to be a mouse hole in Sector 1, but that location appears outdated.

Quick note

A recent post about Crab Lab also suggests players are still looking up animal-style transformations and secret access methods in the game, so this is a common hidden feature people search for.

TL;DR: shrink down, find the mouse holes, gather the code clues, and use the code to unlock the morph room.