First thing that comes to mind is a House wren, they can and will poke holes in other birds eggs and throw them from the nest. However they normally don't leave any left, the will poke them all and or throw them all out. Unless it got interrupted while doing so, if the Blues returned and chased it away. The Bluebird would not normally take an egg out. There are many times one egg doesn't hatch for some reason and they just leave it right there and don't ever take it out. I would keep any eye out, hopefully they don't give up on the two remaining ones but if it was a wren it will probably be back. Good luck! Donna

I would remove the whole nest and let her start over. If she builds a nest on top of the nest it will be to high and starlings and bluejays might be able to reach in the box and grab a baby. Good luck with this nest! Karen

tnjoseph....they lay one egg per day until the clutch is complete. Check tomorrow afternoon, you should see another egg. Don't check in the morning as that is typically when they lay eggs. Knock sofly on the box before opening or talk a bit so she knows you are coming if she is in there. Once she is done laying she will start incubating..incubation typically starts the day the last egg is laid. Incubation is normally 12-14 days and then hatching occurs. Typically 14 days is the norm. Once hatched the nestlings are in the box 16-19 days before they fledge. You can look to make sure all is ok but don't open the box after day 13 to prevent premature fledging. Agree with Nicknack...get a spooker up asap! Glad to hear you got so many HOSP..hopefully they don't bother you anymore. Donna

Do you have any idea about how old the babies were when they disappeared? Bluebird babies stay in the nest ABOUT 18 days, give or take a day, after they hatch. If you know when they hatched (you should always keep records) you will know how old they were. If they were 17 or 18 days old they may have just fledged normally from the nest. If they were younger than that they may have been the victims of predation by anything that could reach them. If they fledged normally you may not see them for weeks; they do a very good job of hiding for the first weeks. The eggs you dropped may have been old eggs, especially if they were buried in the nesting material. Please remove that ornamental box now and go to the Sialis website that Michelle posted for you. You will be able to make a proper setup for the next Bluebirds in your yard. Do it soon, if you can, in case this mother bird wants to lay more eggs. Good luck. www.sialis.org