What are two ways Napoleon leads the outside world to believe that food is plentiful on the farm?

Napoleon left various hints for Whymper to see, thus, word was spread in the countryside. The sheep were given the task of talking about an increase in rations. Food bins were then filled with sand and topped off with food. Thus, it looked like they were well supplied.

He fills the silo with sand and then puts the rest of the grain on the top to make it seem as though the food supply is plentiful. The pigeons are spreading the word that farm is prospering to other animals.