Radiation can cause breaks in human chromosomes. However, insects can survive much higher lecels of exposure. Why?

The influence from radioactivity is inversely proportional to the number of chromosomes, since, humans have more DNA, chromosomes than the insects, and therefore, due to less chromosomes in insects, they are more resistant towards radioactivity.

As the target of the radiation is the DNA.

Hence, It is clear that insect due to lesser DNA are less prone to Radiations.