It's kind of funny that whenever archaeologists find something they have no idea what it is, it's assumed to be a religious artifact, but when a fairly intelligent animal does something weird, we don't say "it must be for religious reasons"...a long time ago I read a science fiction novel that explained the lack of communication with cetaceans by their having religious sensibilities that prevented them from responding. Eventually, communication was established, but the religion was still incomprehensible to humans.