The tale begins with Tommy Brock, a badger, being entertained by old Mr. Bouncer, the father of Benjamin Bunny. Mr. Bouncer has been left to tend his grandchildren while his son and daughter-in-law Flopsy are away, but, after smoking a pipe of rabbit-tobacco, he falls asleep in Tommy's company. Tommy puts the bunnies in his sack and slips out. When the parents return, Benjamin sets off in pursuit of the thief.
Benjamin finds and brings his cousin Peter Rabbit into the rescue venture, and the two discover Tommy has invaded one of Mr. Tod's homes. Mr. Tod, a fox, has multiple homes but keeps moving. Often Tommy lodges in his homes. Peeping through the bedroom window, the rabbits see Tommy asleep in Mr. Tod's bed, and, peeping through the kitchen window, they see the table set for a meal. They realise the bunnies are alive, but shut in the oven. They try to dig a tunnel into the house but hide when Mr. Tod suddenly arrives in a very bad temper, which has caused him to move house.
The fox discovers the badger asleep in his bed, and originally plans to hit him, but decides against this due to the Badger's teeth. He decides to play a trick upon him involving a pail of water balanced on the overhead tester of the bed. Brock however is awake, escapes the trick, and makes tea for himself in the kitchen. Mr. Tod thinks the bucket has killed Tommy and decides to bury him in the tunnel the rabbits have dug, thinking Tommy dug it. When Mr. Tod discovers Tommy in the Kitchen and has tea thrown over him, a violent fight erupts that continues outdoors. The two roll away down the hill still fighting. Benjamin and Peter quickly gather the bunnies, and return home in triumph.

Question: Why does the digging stop?
Answer: Because Mr. Tod returns.
Alternative answer: Mr Tod arrives in a bad temper.