Snakes video: https://youtu.be/TxcOU2FFh8c
Cricket (Katydid video): https://youtu.be/Toe7XZ3dBT4 Scientists have accents so they are a little harder to understand. For kids who want a challenge!! Video is incredible, showing live Katydids and where their ears are! Crickets have three segmented feet, while katydids have four. But, apparently, the difference is easier to hear then to see: while the cricket sound is more musical to the human ear because the sound is pure and low, the katydid song sounds more buzzing, high and less pure.
Elephants: Need to know this word to understand video. Infrasound, sometimes referred to as low-frequency sound, is sound that is lower in frequency than 20 Hz or cycles per second, the “normal” limit of human hearing. https://youtu.be/uQfDazQ9Rkg OR https://youtu.be/eH1vaFsNV8w(This one is easier.)