Weird job...

[Johny B Good]

That's more informative. The louvres seem to on a 1.4cm pitch which suggests (assuming a 45 deg angle) a 1cm gap through which a small bird might possibly have squeezed itself through but it begs the question as to what could motivate a small bird to go to such lengths to gain such entry.

An ornithologist might have a better idea as to what sort of gap something about the size of, say, a blackbird fledgling, could squeeze itself through. Even assuming a bird had managed to squeeze through the louvre, it does rather beg the question as to why it didn't squeeze its way back out again.

In what sense?

[John Williamson]

Looking for a safe nest site?

It panicked and damaged itself?

Sherlock Holmes.

[Vir Campestris]

What's wrong with them?

Andy

[Cursitor Doom]

There are multiple accounts of frogs being found alive inside hollow stones that have been broken open. They typically aren't in terribly good shape and die soon after being liberated. If that can happen then just about anything's possible!

[Cursitor Doom]

There's another possibility, albeit remote and bizarre: an aport!

[Johny B Good]

That sounds quite plausible unless an ornithologist cares to jump in with an objection.

Another plausible explanation (assuming it had managed to sqeeze itself through the louvres in the first place). Unless a bird expert says otherwise, I'd accept that as the most likely possibilty, at least for now.

Just as I was reviewing my post, it finally struck me that it was most likely to be a smoking pipe reference rather than a ventillation pipework one. :-)

[Johny B Good]

The advent of "The Egg" in nature precedes even the dinosaur age which precludes it arriving _with_ the first appearance of the dinosaurs. The MK1 Egg precedes even the sea creatures from which the dinosaurs had evolved from.

[PeterC]

When the noise was heard it could have been a bird or something else; it became a bird only when you looked, thus it didn't get in there - you caused it to be there by thinking that it might be a bird and looking.

You are Schrödinger AICMFP.

[Jethro_uk]

Many years ago (late 70s) we had a couple of cubic yards of bricks stacked in the back garden, waiting for my father to finally get around to building the extension.

Early summer (May ?) my brother and I found a couple of frogs hopping around the garden. We managed to catch them, and for some reason, placed each frog in between two bricks, "frog" side in, like a little cell.

And then forgot about them.

Summer almost passed, and finally, in September, father starts building the extension. My brother and I had the important job of keeping him, and his mate supplied with bricks, from the aforementioned stack.

Went to pick an upside down brick up, and to our astonishment, the frog we had entombed there 4 months earlier, jumped out, and hopped off into the grass.

We then picked up the next brick, remembering we had 2 frogs. In the little cell was a completely desiccated or mummified frog.

To this day, I can't explain it.

[The Medway Handyman]

Makes perfect sense. Thanks.

[Vir Campestris]

The last 5 words were "and birds were still dinosaurs". They sound OK to me.

You're right though - eggs are probably a prokaryote invention.

Andy