Are your customers bees or flies?

I wonder whether the linked article's author actually knows when and whether to use an apostrophe.

Plural: "bees".

Possessive: "bee's".

Plural possessive: "bees'"

http://www.grammarbook.com/punctuation/apostro.asp

When I see an egregious error like this in an article's title, I immediately dive into the article itself, eager to read the words of someone so obviously skilled in the use of words.