From the unconventional and awe-inspiring to the hilarious and heartwarming, here's a look at some of the most interesting photos, videos and stories that have our newsroom talking today. What's capturing your attention, filling your inbox and cluttering your Facebook/Twitter feed? Tweet us the stories you're talking about using #InstantIndex, or email us at ABC.WorldNews@abc.com, and they could appear on "World News."

Mutts Allowed in Westminster Dog Show For the first time in 138 years, the Westminster Kennel Club Dog Show, the gold standard for canines, will allow mutts to compete, at least in the agility contest. All other prizes, including Best in Show, will still be only open to purebreds. The mutts will have their shot next month when the Westminster Dog Show comes to Madison Square Garden in New York.

The Aerodynamics of Birds' 'V' Formation New research out Wednesday claims that the bird's "V" formation you see in the sky is really a genius of aerodynamics. Each bird has an assigned position and each flap of the wing is precisely timed to conserve energy. They capitalize on the burst of air from the bird flapping in front. The bird in front takes a whopping 40 percent of the brunt of the headwind, lending a hand to those in back.

(Mirko Stelzner/Newscom)