Caution Bee

Found this sign, which was just taped on the wall near a university library. Due to the way it is presented and its nature (it's nothing but a piece of printing paper), this sign appears to lack in authority; still it would be highly effective, the recipients will beware of bees as indicated, for bees are what most people dare not have close encounter with.

Its somewhat poor appearance for a public sign may also imply that what it's communicating is of temporal risk.

There are similar signs around the campus, too, as my uni is located in the mountains. As far as I know most of them are put on the walls or windows with adhesive tape just like this sign is, and when there is no risk they may be simply removed.