What do you call 10 rabbits walking backwards? ... A receding hare line!

 What building has the most stories? The library, of course!

 A frog walked into a library and asked the librarian what he would recommend. 

"How about this sir?" asked the librarian, showing him Toad of Toad Hall. 

"Reddit, reddit," said the frog.

 A young boy refused to do his homework, and his father was trying to convince him to do it. He said to his son: "When Abe Lincoln was your age, he was studying books by the light of the fireplace." 

The son replied: "Well, when Lincoln was your age, he was President!"

 A neutron walks into a bar, sits down and asks for a drink. Finishing, the neutron asks "How much?" 

The bartender says, "For you, no charge."

 Upon entering a little country store, a stranger noticed a sign reading, "Danger! Beware of Dog" posted on the glass door. Inside, he noticed a harmless old hound dog asleep on the floor besides the cash register. He asked the store manager, "Is that the dog folks are supposed to beware of?" 

"Yep, that's him," he replied. 

The stranger couldn't help but be amused. "That certainly doesn't look like a dangerous dog to me. Why in the world would you post that sign?" 

"Because," the owner replied, "before I posted that sign, people kept tripping over him."