I notice that saliva seems to clean well, much better than plain water. For example, tar spots on the car can be difficult to get off. I typically use really powerful solvents to get them off, like 95% acetone and things like that. Yet, saliva works too.

Why is this?

  • $\begingroup$ Saliva has proteins which act like mild surfactants (detergent effect) and of course mechanical abrasion helps to physically dislodge the spots. $\endgroup$ – M. Farooq Nov 24 '19 at 23:27

Saliva has alpha-amylase (ptyalin), which hydrolyzes carbohydrates (so starch starts to taste sweet in just a few seconds), kallikrein, an enzyme that breaks down protein, and lingual lipase, which helps disintegrates fats (lipids).

So next time you clean off a splattered insect from your wind-screen (windshield, should you prefer), think of it as external digestion, as practiced by flies and by starfish. Or perhaps you might not want to consider that thought...

| improve this answer | |

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.