Any guesses what this is...
There's this National Geographic Wild show called Live Like an Animal. What these folks do, is choose an animal (I believe they did beavers in London for another show) build their living environment, and then live like that animal for 24 hours.
This rounds animal...a hummingbird.
My understanding is...since hummingbirds eat their own weight in nectar each day...three men will be not only living in the nest, but eating 80 liters of sugar water, and whatever beef jerky they can catch as it's catapulted to them. (Replicating bugs that hummingbirds catch.) Yum...not:/