These fake eggs may be able to expose the illegal trade of endangered turtle eggs.
They are 3D-printed egg decoys with hidden GPS trackers.
Developed by conservation organization Paso Pacifico, they were invented to address the illegal trade in Central America, where eggs are smuggled from beaches and sold as a delicacy.
Here's conservation biologist Helen Pheasey from the University of Kent, who led the project.
"Our main objective for this project was to test the technology. We just wanted to see if it actually worked. Is it possible to deploy an egg in a nest and trace the entire trade chain? And that's what we succeeded in doing."
The team made sure that the eggs were as realistic as possible.
"The actual aesthetics, if you like, are it's very spongy, it's very rubbery, just like a turtle egg"
In total, 101 decoy eggs were deployed throughout the project, with 25 taken by poachers.
Pheasey said early evidence showed the majority of stolen eggs don't leave the local area.
But tracking did lead to a few surprises, where one egg travelled over 85 miles.
"I actually zoomed in - literally on my mobile phone app from Google Maps - zoomed in and I was able to identify the exact supermarket where it arrived, but it hadn't gone into the supermarket. It was round the back. It was like in some back alley. Why would you be there with turtle eggs if you're not doing something somewhat suspicious?
No legal action was taken as a result of the project.
But Pheasey said the team is working towards making these decoy eggs as a law enforcement tool.