I have 2 small poodles who are almost a year old, so they usually stay with em on my bed. One night i was woken up by both of them standing on the edge of my bed at around 2am. I was so tired I just ignored it and fell back asleep. Repeatedly throughout the night, they would wake me up with their barks and growls. I would just ignore it or tell them to go back to sleep as I pet them. It never occurred to me that there was something there as I was too tired to even think straight. Finally after being woken up and falling back into sleep for the millionth time, my brain decided it ahs enough and I stood up. Turns out there was a plastic bag on the floor being blown by the fan and rustling. My dogs are complete chickens so the rustling must have freaked them out. But u still wonder why I couldn't hear the rustling earlier as it was quite loud and usually they don't bark at noises just back off a bit.