Calcium Nodules on Eggs

At some point during your time of working with chickens, you might encounter eggs that look like they have insect eggs on them. The view can be disquieting at first—all sorts of images could go through your mind. However, it’s more likely that what you’re actually seeing are calcium nodules that merely look like insect eggs. Here is an egg that has such nodules on it.

An egg may have harmless calcium nodules that look like insect eggs deposited on it.
Calcium nodules can look like insect eggs.

These nodules are completely harmless. In fact, you can wash them off the eggs quite easily. When crushed, the nodules feel gritty, much like crushed eggshell would feel. These nodules typically appear for two reasons:

The first reason is the one that occurs most often. Five of my hens are now four years old and one is five years old. The five year old hen (a Black Australorp) laid this egg, so the nodules aren’t unusual at all. (Most factory settings keep laying hens for one or two years after they start laying eggs, I’ve found that four years in optimal settings works well.) This spring I’ll replace two of the hens with new layers (the other four are pets and will die of old age). I also had one hen eaten by hawks and another died of an impacted egg, so I’ll actually get four new layers this spring.

I’m thinking of trying Barred Rocks (a kind of Plymouth Rock) because I’ve never had them before and they’re quite pretty. According Henderson’s Chicken Chart, they’re cold hard and produce large eggs. A friend of mine has them in her flock and feels that they’re a good investment. The point is that when you start seeing these nodules on one or two eggs and not on the eggs of your flock as a whole, you may need to start thinking about replacing the bird that laid it. Let me know your thoughts about keeping a healthy flock at


Author: John

John Mueller is a freelance author and technical editor. He has writing in his blood, having produced 99 books and over 600 articles to date. The topics range from networking to artificial intelligence and from database management to heads-down programming. Some of his current books include a Web security book, discussions of how to manage big data using data science, a Windows command -line reference, and a book that shows how to build your own custom PC. His technical editing skills have helped over more than 67 authors refine the content of their manuscripts. John has provided technical editing services to both Data Based Advisor and Coast Compute magazines. He has also contributed articles to magazines such as Software Quality Connection, DevSource, InformIT, SQL Server Professional, Visual C++ Developer, Hard Core Visual Basic, asp.netPRO, Software Test and Performance, and Visual Basic Developer. Be sure to read John’s blog at When John isn’t working at the computer, you can find him outside in the garden, cutting wood, or generally enjoying nature. John also likes making wine and knitting. When not occupied with anything else, he makes glycerin soap and candles, which comes in handy for gift baskets. You can reach John on the Internet at John is also setting up a website at Feel free to take a look and make suggestions on how he can improve it.