Although it often feels like we have enough to deal with, we can nonetheless find ourselves facing warning signs we didn't even know we had to worry about.
For instance, if you see a purple flag on a lifeguard tower, it means that your day at the beach could end up interrupted by some hazardous marine life. Depending on the time of year, it's likely to be "sea lice" that can cause itchy rashes with their stings.
By a similar token, there's a decent chance that this could be the first time that you've been warned about hanging around a building that appears to grow fur.
As with the sea lice, ignoring this warning won't put you in mortal danger but it will probably make things a lot less comfortable for you.