You often see many rats on the rail tracks in Mumbai. So I started to form a heroic image of them in my head: Rats, the true survivors. Because really, do they really want to hang out in sewers or is it just that they can without being killed!
Further investigation into the evolution of the city rat, led me to the lesser highlighted information of our genetic cousins:
A 2011 controlled study found that rats are actively prosocial. They demonstrate altruistic behaviour to other rats in experiments, including freeing them from cages. When presented with readily available chocolate chips, test subjects would first free the caged rat, and then share the food. All female rats in the study displayed this behaviour, while 30% of the males did not.
And if they write this (the below) about rats, I wonder what could be said about the humans :)
Rats as invasive species(Source: http://en.wikipedia.org/wiki/Rat)
When introduced into locations where rats previously did not exist they cause a huge amount of environmental degradation. Rattus rattus, the black rat, is considered to be one of the world's worst invasive species.As part of island restoration some islands have had their rat populations eradicated to protect or restore the ecology. Hawadax Island, Alaska was declared rat free after 229 years and Campbell Island, New Zealand after almost 200 years. Breaksea Island in New Zealand was declared rat free in 1988 after an eradication campaign based on a successful trial on the smaller Hawea Island nearby.