Animals in Writing

Everyone loves playful puppies and cute kittens, right? Here's how they can provide much more than simple adorableness in a story:

• Characterization: yes, you can give the animals character (in fact, I hope you do) but they can also reveal things about your main character. What kind of pet does she have? What did she name it? How does she treat it? How does she treat her neighbors pet? How does she respond to other characters interacting with her pet?
• Comedic Relief: so, it wasn't the evil stalker vampire sneaking in at the middle of the night this time, but the puppy getting tangled in the sheets?
• Plot devices: "..... what's that strange thing Furball has in his mouth? Is it a magic amulet? Evidence from a crime scene?"
• Motivation: Yes, so it might be a bit far fetched to have the bad guy kidnap the hero's trusty pet, but if the cat gets out, would the kid not be more likely to approach the scary forest he had promised never to go into?