Eyelashed

Amazed at the length of Poppy's eyelashes and remembering what I thought was possibly true but maybe a myth from my schooldays, I somehow ended up reading this;

Demodex folliculorum(the demodicid), is a tiny mite, less than 0.4 mm long, that lives in your pores and hair follicles, often in the roots of your eyelashes. Demodicids have a wormlike appearance, with legs that are mere stumps. People with oily skin, or those who use cosmetics heavily and don't wash thoroughly, have the heaviest infestations ... but most adults carry a few demodicids. Inflammation and infection often result when large numbers of these mites congregate in a single follicle.

So, only adults are effected. Poppy's eyeslashes are hopefully clean of weird alien worm type mini-beast creatures(relief).. What I'd really like to know is where do they come from and how do they get there?