Reader and friend of this site, Melanie, sent in an amusing anecdote. It turns out to be an object lesson in how we can deceive ourselves however, so the story is being told here with Melanie's permission.
Melanie's mother called her one Sunday in a panic stating that she had a bird trapped in her loft or somewhere under the eaves. It must have got trapped sometime on Saturday, as that's when it started to make a noise. Thankfully for her mum, the bird seemed to sleep until morning.
On Sunday, it was making one hell of a racket; she could hear it calling out and flapping its wings. After going outside to inspect further, Melanie's mum could see the bird's beak now and then as it was attempting to poke its head out from under the eaves.
Melanie contacted the RSPCA on her mum's behalf and asked them if they could help. They wanted more specific information as to the bird's whereabouts however, before they would send someone out; so Melanie went around to her mum's to investigate.
When she got there, Melanie had to agree with her mother that it did make a lot of noise; only the bird sounded exactly like a smoke detector with a flat battery. Problem solved.
How did the "bird" seemingly go to sleep during the night? Answer at the bottom of the article.
The lesson of the story
This is a classic example of how our senses can deceive us. Whenever sensory information is scant, our brain has a tendency to fill in the missing information as best it can. Melanie's mum heard the bleeping of a smoke alarm with a flat battery. Being hard of hearing, and never having heard a flat smoke alarm before, she interpreted the sound as the squawking of a bird. As the squawking continued she assumed that the bird was trapped. That is entirely understandable.
Now, once mum thought that this bird existed, she also heard it flapping its wings and when she went outside to look for it even saw it poking its beak out. Again though, this is nothing unusual. We have an inbuilt tendency to interpret things in accordance with our expectations.
Melanie's mum truly believed that this bird existed because she'd heard it, then seen it.
Many people truly believe that they have seen a ghost, a UFO, Nessie, or Bigfoot. The critical question is: did they really see what they thought they had seen or was it their brain filling in information? Either way it will seem just as real to them.
It is quite easy to accept that the "bird in the loft" didn't really exist, as an explanation for it was found. The problem with transient sightings such as ghosts etc. is that the explanation is not usually found: it can only be speculated. Without a solid explanation, people find it hard to accept that their experience may be down to their interpretation of events rather than being real.
This humorous example shows just how easy it is to form a wrong conclusion through the unconscious misinterpretation of sensory information. People who report having seen or heard unusual things are undoubtedly sincere, but may well be mistaken.
Answer to why the "bird" apparently went to sleep: Melanie's mother takes her hearing aid out when she goes to bed.