Why do old books smell?

Why does an old book smell like grandpa's closet?

Mental Floss answers readers' questions, and apparently enough people don't understand how things die. (Psst: Heads-up...you're going to die someday, too.) So the explanation?

Books are made of organic material, and that organic material reacts to its environment (light, temperature, moisture, etc.). When that organic material decays--and all of it will in time--it releases volatile organic compounds (VOCs), which release a scent. As macabre as it sounds, this is why animals (and you) smell when they die, too.

According to Mental Floss, scientists have found a selection of compounds (in the form of VOCs) that keep showing up in dying books, from acetic acid and butanol to octanol and benzaldehyde.

In case you're wondering, benzaldehyde is also known as artificial almond oil, and is often used today as a food additive to make the food smell extra deliciously nutty.

Mmm, delicious dying books!