It’s not just being thirsty that makes mice eat salt—only when the angiotensin signal is present does turning on salt-craving cells make them lick salt, not when they’re just dehydrated.

Just turning on the salt-craving brain cells doesn't make mice eat salt fast—unless you also trigger the angiotensin signal, then they immediately start licking salt like crazy.

The same brain cells that sense low salt also have a built-in alarm for angiotensin, a hormone that signals low blood volume—so they respond to both signals together.

The salt-craving brain cells connect directly to a specific spot in the brain called the vlBNST—turning on just that connection makes mice drink salt water, even without other triggers.

If you remove most of the salt-craving brain cells, mice no longer seek out salt—even when they’re very low on it.