"Rats have almost no bones and are quite rich in nutrition"
Nutritious they may be, but I can assure Mr Prakash that they have more bones than a human being!
Of course, a lot of the bones are tiny, and probably crunchable/swallowable, like some fish bones...
I suppose it's not so different from eating rabbit, bit gamier I suspect. Depends what the thing's been living on too - a rat living on a dump of human rubbish might not be such a gret proposition as a plump corn fed one...