But get this-cockroaches are radiation wimps compared to some other insects. Adult fruit flies have survived doses of 1600 Grays, and some ant species can handle doses up to 2250 Grays. We don’t really know what gives insects so much better radiation resistance than us. Radiation penetrates their cells as well as it does ours. Scientists suspect that one reason could be that insect cells usually contain fewer chromosomes, and so less DNA, than mammal cells. Since radiation poisoning is the result of destruction or mutation of DNA, having relatively less DNA in your cells may make it easier for those cells to survive radiation exposure.