> I wonder if pets in households with those talking buttons ever use them to communicate with each other, or if they never choose to because it's so much less efficient than natural conspecific communication for most of the things they would want to 'talk' about.
I haven't yet seen an example of it. I think pets learn to use the buttons to make requests or answer them, but they never do that with each other because they never really have any requests or answers for each other, if that makes any sense.
Correct. Dogs will vocalize and use touch with one another but the buttons are exclusively (at least from what I've observed) used for communicating with people. Though dogs & cats have specific vocalizations for speaking with people. Though we're now seeing vocalizations in new species that we didn't expect such as plants[1] & turtles[2].
I haven't yet seen an example of it. I think pets learn to use the buttons to make requests or answer them, but they never do that with each other because they never really have any requests or answers for each other, if that makes any sense.