1. How do birds pee?
2. Can sleeping in a fridge kill you?
3. Why do chickens have red flappy bits on their heads?
4. Do fish get thirsty?
Fish don't technically drink water like we do. Instead, it diffuses through their body from the surrounding water in a process called osmosis. How exactly this happens depends on whether they live in freshwater or seawater.
According to aquaculture specialist William Wurts writing at Scientific American:
In seawater, fish must drink salt water to replace lost fluids and then eliminate the excess salts. Their kidneys produce small volumes of fluid containing high concentrations of salt. Freshwater fish produce large volumes of dilute urine, which is low in salt. Less demand is placed on the kidneys to maintain stable concentrations of blood salts in brackish or low salinity waters.
So all fish do need to take in water, but they probably don't ever actually feel thirsty.
5. How do cats have sex?
6. What's the highest anyone has ever counted to?
7. How do we know what noises dinosaurs made?
Here's a fun fact: The dinosaur sounds you heard in Jurassic Park were actually animal sex noises.
It's not been easy for scientists to work out what dinosaurs would have really sounded like, because the vocal cords they presumably used were made from soft tissues and did not get fossilised. But we can look to their closest living relatives to put the puzzle together.
According to Joe Hanson at It's Okay To Be Smart:
The deep groaning vibrations used by crocodiles and reptiles come from the larynx. Much like in our own vocal chords, air from the lungs vibrates folds of tissue to create rather intimidating vibrations that sound like this. Birds, on the other hand…or wing…use a structure called the syrinx, which is close to a larynx but probably evolved independently. That means that roars and rooster calls could have a different evolutionary origin. One, both, or neither of those structures may have existed in various families of dinosaurs.
Some features possibly related to sounds made by dinosaurs have been fossilised, like the lambeosaur's crest. According to the University of California, Berkeley: "The most accepted theory today of the function of the crest is that it served as a resonating chamber, allowing lambeosaurs to make deep, loud sounds."