Why caterpillar should not be collected with bare hands?

Question

Why caterpillar should not be collected with bare hands?

Answer 1

Some caterpillars have hairs which can cause irritation to the skin and respiratory system of humans and animals - it's a defence mechanism.  The scientific name for this is "urticating" hairs.

One particularly irritating caterpillar (or rather its hairs) is the caterpillar of the Pine Processionary moth - the hairs can be fatal if inhaled by pets, and can cause a serious allergic reaction in certain vulnerable people. Here is a good link to an article about the caterpillar of the Saddleback moth, another species with urticating hairs http://en.wikipedia.org/wiki/Saddleback_...

Some spider species also have urticating hairs.

Answer 2

Some caterpillars have stinging hairs on them... trust me, you don't want to touch, step on, or brush up against them.