They just don't care lol.
I recently cleaned my car after being crapped on. Due to my stupidity because of work, they'd been on the car for a few days. I noticed after cleaning off the poos, there are now paint blimishes (tiny bubblage) and I can't do anything about it but have parts of the car repainted. Spots are located on the trunk nearest the window, roof and rear side.
Because the car's a year old with rental scratches and other scars I'm not gonna stress too much over it. My advice is to carry bottled water and towels at all times. Bug and tar removal would work better.
2010 Cobalt 2LT Victory red Coupe
Mods: Tinted 50% ceramic all around, factory spoiler, 2008 LE5 2.4 Throttle body, GMPP Intake, Walker stock exhaust system (back to silence), TruBendz/MBE 2.5" catted Downpipe, HP Tuners by Chenry Motorsports, Alpine CDE-151 with USB port, Rockford Fosgate 300-10