There are many difficult achievements in "Frost Age 2", and doing nothing is the devil's plaything is one of them. To achieve this achievement, you only need to make at least 90% of the population in your city active workers. This is still It’s more difficult because you need to increase the labor ratio.
How to get the achievement "Idleness is the devil's plaything" in Ice Age 2
Idleness is the devil’s plaything
The labor force accounts for at least 90% of the total urban population.
Make at least 90% of the population in your city active workers
Increase labor force ratios by passing good laws. Build automated labor factories to create automatons and increase the workforce without increasing the population.