Related Clues:

• Porcupines, prairie dogs and pack rats
• Porcupines and prairie dogs
• About 40% of mammal species
• Mammals with continuously growing incisors
• Mice and the like
• Squirrels and chinchillas, e.g
• Squirrels and rats
• Creatures that make some jump on chairs
• Gnawers such as rats
• Mice, e.g
• Mice and beavers, e.g