When female mosquitoes are looking for a human to bite, they smell a unique cocktail of body odors that we emit into the air. These odors then stimulate receptors in the mosquitoes' antenna. Scientists have tried deleting these receptors in attempts to make humans undetectable to mosquitoes. However, even after knocking out an entire family of odor-sensing receptors from the mosquito genome, mosquitoes still find a way to bite us. Now, a group of researchers found that mosquitoes have evolved redundant fail-safes in their olfactory system that make sure they can always smell our scents.