I see those signs all the time (Do Not Mow) its usually for private residences that dont want the state/county/city to mow their property. The weirdest signs ive seen are. Donkey crossing in Hawaii, Diamondback Terrapin Crossing in Tybee Island, GA and tank crossing somewhere in GA.
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Catapultam habeo. Nisi pecuniam omnem mihi dabis, ad caput tuum saxum immane mittam.