This is the final Taxing level, "Lem me your ears". You have 10 lemmings and must save them all in 10 minutes.
After the first lemming takes a few steps, turn him into a Digger.
Give the Digger the Climber ability as well.
Right in the middle of the non-striped part of the upper platform, have the first lemming to come out of the upper entrance build steps to avoid the trap.
The second lemming on the upper level will need to dig downward.
Have the Climber build steps at the farthest right you can get, without falling into the pit.
The second and third lemmings up above should dig downward, right after the trap and before the non-striped part of the platform.
Have the first upper lemming dig down through the chain if needed.
Make sure the Climber keeps building rightward.
Let the upper lemming walk all the way to the right and turn around. As he's walking left, turn him into a digger, on the left side of the big gear. If he doesn't dig all the way through the gear, you can use a Basher leftward to finish the job.
Have the Climber continue building again.
Have the lemming that's on the right side of the pit build steps leftward, right on the very edge of the platform.
Have the Climber keep building.
Have the other building keep building.
If done right, the Builders should join their steps up with no room to spare.
Have one of the trapped right-walking lemmings build steps to climb their right wall.
The lemmings should now make it out of the pit they were trapped in.