Rat is the biggest problem for pest control. Rats are crawling in every corner of the globe, it’s not entirely because of fortunate circumstances. Rats adapt to different environments without much difficulty. A rat can go even longer without water than a camel. It can fall some five stories without being hurt. They can survive massive doses of radiation, and swim for half a mile across open water. Over generations, they tend to build up certain immunities against poisonous and toxic materials. And the biggest, feistiest sewer rats can scare average house cats running.