It was then further noticed that when the weather started getting warm and the birds began singing, the eggs would hatch sooner, leaving them with less size. A smaller size is helpful for babies in regulating their temperatures in the hot summer heats.
Mylene Mariette from Australia's Deakin University said: "We didn't realize that they were able to hear before hatching."
Learn more about this at sky.com
What are ways you like to stay cool in Hot Places?
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