According to a study published in Nature Neuroscience, the act of mating induces permanent chemical modifications in the chromosomes.
Nature News reports that these changes then affect the expression of genes that regulate sexual and monogamous behaviour.
In a statement, the researchers explained: "Formation of a specific partner preference in female prairie voles involves changes in their gene structure that do not alter the DNA sequence, but influence genetic expression.
"These so-called epigenetic changes occur following mating, which is known to cause lifelong pair-bonding in prairie voles, a socially monogamous species."
The researchers conclude that similar changes could happen to other species as well.