Walljumping is a method to climb up straight walls. You do this by jumping against them, then jumping up and from them, but returning to the wall at a higher point. You then repeat this process until you have jumped up the entire wall. To walljump, follow these simple steps:

• Jump against the wall you want to get over.
  
• As soon as you touch the wall and see your mouse begin the running animation against the wall, immediately jump up and away from the wall.
  
• After a short while, when you have got a short distance away from the wall, change direction so that you are moving towards the wall again.
  
• If you do this correctly you should hit the wall and begin running against it, at a higher point than you originally were. Jump away from the wall as soon as this happens, and repeat the above steps.

Walljumping takes a lot of practice to get really good at, but as soon as you "get" the basics it's easy to improve. I recommend practicing your walljumping against normal light wooden walls at first, though you will also learn to walljump other materials later on.

Additionally, it's harder to walljump while you are carrying cheese than without cheese. This is because cheese weighs you down and makes you fall faster. Because of this, you should start practicing walljumping without cheese.

For more info on walljumping, you can visit the Transformice Wiki page[transformice.wikia.com] on the subject. Thanks for taking your time to read my guide, and may the cheese be with you.