Strangest nest I've ever seen in my bluebird house....

Something went to great lengths to enlarge this hole...

This is a close up of what the little rascal did.

So, with my curiosity aroused, I opend the side viewing door to see what was inside...

A close up of the strange looking mud ball. My first thought was "No wonder it had to enlarge the hole...to get that big ball inside." But actually, the rascal probably built it in there. I work during the day, so I never noticed what was building this. Does anybody know the culprit?

I'm watching, but I haven't seen anything around just yet.

Pam

Wow that is different. Can't wait to hear what it is doing that.

I'm currious too...

Pretty freaky!

Is the mud ball solid? There's no opening, and the weight doesn't seem like it's hollow? (ETA I'm wondering if it's a dirt dauber-ish thing, something that builds a nest from mud and maybe chewed wood. They didn't know your box was already a nest box, it just seemed warm and dry, like building under the eaves or the deck or such.)

The hole enlargement doesn't look gnawed, there are no tooth marks like a rodent?

I'm going with dung beetle for now...

This message was edited Mar 28, 2010 10:54 AM

LOL, I was thinking the same thing. :-)

The ball thing inside might be some sort of wasp nest; I'd guess a woodpecker heard the noise they made, and opened up to try to find something edible in it.

I'd remove the ball (safest done on a cold morning, in case it is something that can sting), and put on a stronger steel plate over the hole to prevent further excavation.

Resin

Woweee, went thru the metal and everything! I've never seen anything like this. I'm looking forward to an answer too!

What bird is the birdhouse for?

squirrels do that every year to my bluebird houses when they sit vacant for any length of time. we take a piece of tile and make a hole the same size as before and glue it to the front. as far as the mud ball, i'm thinking it must be a mud dauber but i'd take it out as suggested.

I agree, probably a Mud Dauber nest: http://images.google.com/imgres?imgurl=http://www.ent.iastate.edu/images/hymenoptera/sphecidae/sphecinae/muddaubnestfl.jpg&imgrefurl=http://www.ent.iastate.edu/imagegal/hymenoptera/sphecidae/sphecinae/muddaubnestfl.html&usg=__cz-1VA1zgafptf5Bk4F2Gs-Wv4U=&h=338&w=432&sz=37&hl=en&start=3&um=1&itbs=1&tbnid=_YcaGjpkwrIeSM:&tbnh=99&tbnw=126&prev=/images%3Fq%3Dimages%2Bof%2Bmud%2Bdauber%2Bnests%26um%3D1%26hl%3Den%26sa%3DX%26tbs%3Disch:1

And, I'd almost bet it was a woodpecker that enlarged the opening ... I've had Red-bellied Woodpeckers do that to a birdhouse or two that are on posts out in the yard.

I'm betting squirrel too since it chewed thru the metal.

Hi everyone! I didn't see any activity at all yesterday. So after reading everyones comments today, I think I shall carefully remove the mud ball. There is no visible opening on the ball from the window that I can see.
The birdhouse is suppose to be for bluebirds. We do have a lot of woodpeckers and squirrels here. (and wasps too)

Thanks for all the great input!
Pam