Scientists found that over time, hummingbirds are beginning to evolve a bigger sweet tooth.
They are also the only known birds to have a sweet tooth, according to Zee News India.
The genetic codes of 10 different species of birds were analyzed and scientists found that the hummingbird was the only one whose genetics draw them to sweet foods, such as nectar.
Maude Baldwin and Yasuka Toda, co-first authors of the paper published in journal Science, found that a single receptor can drive a change in the behavior of a molecule. Hummingbirds didn't always have a sweet tooth, so their new-found attraction to sweetness led them to this finding.
The scientist spent three years cloning the genes in the taste receptors of various birds, finding the proteins in the taste receptors of most of the birds were responding strongly to the levels of amino acids, which are umami flavors.
But not the hummingbird.
The hummingbird was the only one responding to carbohydrates, which are much sweeter flavors.
This was also the first time the hummingbird reportedly showed signs of responding to the sweet carbohydrates.
The study also found that hummingbirds prefer sweet tasting foods better than blander ones, as New Scientist reports.
During testing, the hummingbirds gave scientists a laugh when they found the birds were only attracted to real sugar - they appeared to know the difference between real sugar and artificial sweeteners that we put in our sugar free drinks, according to Irish Examiner.
