Linda wrote:

What's SETI looking for? Life forms able to communicate with us? Life intelligent enough to communicate with other similar life forms? Life that can communicate with my dog?
How are the various SETI projects defining what they are searching for?

    Unless one has the parochial idea that only Homo Sapiens Sapiens (or smarter) is "intelligent" then clearly the I in SETI is not that.

    In this case simply a non-natural source of RF in a narrow frequency range.

    The assumption is something in the HSS range of intelligence range is required to be the cause of that non-natural source. Intelligence meaning outwitting the competition to survival.

    So if humans all ascend like Daniel Jackson and spiders evolve to making RF mating calls of sufficient amplitude to be detected at interstellar distances that will also be non-natural in the detection sense of SETI.