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Moms who are so taken with their babies that they want to “eat them up” have a good biological reason for feeling that way, say researchers.

We already know that mothers and babies have a unique connection to each others’ scents, but the latest study reveals that the olfactory kinship is rooted in the same rewarding feelings that are triggered by food. The satisfaction and satiety that eating brings to a hungry person, or that a drug provides for an addict, are the same that a newborn baby’s aroma elicits in a mom.

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Researchers from the University of Montreal collected the scent of newborns off their pajamas two days after they were born, and asked a group of 30 women to smell them while undergoing brain scans. Half of the women had given birth three to six weeks before the experiment and the other 15 had never given birth.

Although both groups of women smelled the same scent intensity, their brain reactions were notably different. The women who had just given birth had greater activation in their brain’s reward center compared to women who had never given birth. “This circuit makes us desire certain foods and causes addiction to tobacco and other drugs,” the researchers say in a statement. “Not all odors trigger this reaction. Only those associated with reward, such as food or satisfying a desire, cause this activation.”

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That’s because by and large, the reward circuit is designed to reinforce behaviors that are critical for survival, such as eating and sex (although the system can be exploited by less beneficial behaviors such as excessive drinking and drug abuse) — and creating a bond between mother and child. Not only does this provide much-needed protection for the helpless infant, but it also helps moms to become more comfortable with new maternal experiences, including breastfeeding.

The research is published in the journal Frontiers in Psychology.