Why do some animals use high frequency sound waves while others use low frequency ones?

Sounds are simply pressure waves.

High-frequency waves travel a shorter distance because of their higher number of cycles, which means that more energy is dissipated into heat more quickly. Their small wavelength makes them useful for detecting objects, since they are reflected by them.

Low wavelength waves, on the other hand, retain their original intensity for a longer time, and can bend around objects, bypassing them.

For these reasons, social animals that communicate over long distances, such as whales, wolves or elephants use low-frequency sounds. Elephant infrasounds have such a low frequency that they can spread over 10 kilometers.

And because sound spreads faster in water, those of whales travel as far as 1,000 kilometers. Their songs echo through most of the oceans, and it seems plausible that a message of theirs could spread across the entire planet with just a few repetitions.

High-frequency sounds are used when the opposite is required: to find even the smallest obstacles by reflecting them instead of going around them. They are used for this purpose by dolphins and bats, among others.

Communicating with infrasound and ultrasound is therefore, in no small measure, a function of the size of a colony and its range, or a matter of sensory need.