Mont. Code Ann. § 81-20-203

Every person engaged in the business of buying eggs intended for human consumption for resale shall maintain an adequate place for the proper candling and handling of the eggs by an egg grader licensed pursuant to this part or shall purchase only eggs which have already been properly candled and graded under the supervision of an egg grader licensed pursuant to this part. The term "candling" as used in this part means the careful examination, in a partially dark room or place, of the whole egg by means of a strong light.