Rats Make a Special Sound When They Eat Chocolate
Friday, October 16, 2026113 words2 minutes172 reads
Rats make sounds that humans cannot hear. These are ultrasonic calls. Scientists in Japan listened to rats while they ate chocolate, a food the rats liked very much.
They found a special 40-kilohertz call. Its shape looked like an upside-down U on a sound picture. Nearly all of these calls happened within one second of the rats biting or chewing chocolate.
The call was much less common when the rats ate normal food. This may mean that the sound is linked to eating something tasty. But it does not prove that a rat is saying "yum." The scientists recorded pairs of rats, so they could not always tell which rat made each call.
