Riddles Random Riddle: NASA Canaries May 26, 2023April 28, 2023 gags NASA was considering sending canaries into space to study them under zero gravity. The project was scrapped when someone realized that in spite of having sufficient water supplies, they could die of dehydration within a few hours. Why? Show answer Birds, unlike humans, need gravity to swallow. Humans can swallow even while hanging upside down.