The user has a large amount of their kikaichū and has them spread out over a wide area around themselves. The insects then emit a small amount of the their host's respective chakra that they usually feed on. This confuses sensor-type shinobi's chakra-sensing ability, as the insects' irregular distribution and grouping together result in the creation of numerous false 'images' or chakra signals, making it more difficult to distinguish the user's actual location.
The name of this technique is another case of an English word being given kanji, similar to many techniques used by Kumogakure shinobi.
"Mingu" (民具, Literally meaning: folk tools) — as used in the name of this technique — are common, everyday items that have become so symbolic of the traditional Japanese way of life, that they are now regarded as a kind of folk art.