I've posted cameras on public gamelands before. Some cameras have a visible red flash, others do not; the ones that do will attract attention--I had a photo of a guy with a headlamp staring right at my camera and I know it's because he saw the flash. Some of them are made so that a security cable goes around the front so it can't be opened (other hunters have been known to remove the cards when they don't want you to know what they know). I've also mounted them higher on the tree but when I do, it seems that there's always something that keeps tripping the sensor and I get thousands of pics of nothing. My camera can usually do about 2,000 photos before the lithium batteries die, and they are kind of expensive, maybe $15 for a set of eight. I do have these cable locks and they work great:
https://www.amazon.com/Master-Lock-...20517&sr=8-5&keywords=trail+camera+lock+cable