Kiwi, a two-year-old budgie, has heard me say “Hey Siri” many times in the house. I never intentionally taught him this, but eventually we started hearing him say “Hey Siri” at random. Later, we started hearing him also imitate the chime that happens after you say “Hey Siri” and let Siri respond.
Tonight I caught him activating it on his own. I guess the register of his voice in imitation of mine is close enough for Siri to activate. Desperate to catch it on camera, I recorded 6 minutes of him talking to the iPhone. Lo and behold, he activated Siri again! Right before he says it, you can hear him say “My name is Kiwi, I’m a parakeet!”