Carl Linnaeus, The Lapland Journey, translated by Peter Graves (Edinburgh: Lockharton Press, 1995), p. 147.

Jokkmokk [2], 21/07/1732, ¶773:

Reindeer get “korm”-maggots both in the nose and in the gums and when the animals begin to pant in spring the maggots come out through the nostrils. The ripe maggots on their backs are squeezed out to stop them eating the deer and irritating too much. The maggots do not actually live in the flesh but between the skin and the connective tissue; in spring they leave open holes just as they do on cows.