A pun to share

A pun to share 
Three rats are sitting at the hindrance talking bragging here their staunchness and toughness.

The ahead says, "I'm so hard, on a former occasion I ate a chiefly bagful of rat blight!"

The instant says, "Well I'm so leathery, from time to time I was caught in a rat trap and I bit it apart!"

Then the third rat gets up and says, "Later guys, I'm off habitation to beset the cat."