Katy

... did drop in to visit.

She slept in the angle of the ceiling and wall above my desk for two days, then went about her business.

Drumming katydid, female*, Meconema thallassinum

These insects drum on leaves with their hind legs. And they hear their song with an organ that functions like our ears, with a membrane (the typanum) stretched over an air sac. Except that the "ear" is on the front leg, just below the knee.

Front leg, with tympanal organ.

"Do you mind if I drum on your wall?"

*The female has a long, pointed ovipositor at the end of the abdomen. The male has two curved pincer-like appendages instead.

The speaking gaze

A hermit, looking me straight in the eye, seems to be saying, ...

"Are you listening? This is important!"

Unfortunately, I can't hear him.

Do underwater invertebrates communicate with sound at all? Fish and whales do, I know. Land-based insects do. Even slugs detect some sounds. How about crabs and shrimp? Hermit crabs?

Maybe they do.

Although marine invertebrates do not hear in the same way vertebrates do, it is thought they are able to sense vibrations and movements associated with sound production. Some marine invertebrates that produce sound in air have specialized sensory organs that can detect acoustic pressure changes in air. However, marine invertebrates in water are known to detect only particle motion. External sensory hairs and internal statocysts aid marine invertebrates in sound detection.  (From Discovery of Sound in the Sea.)

There's always more to learn and be amazed by.