Scouting is meant to take the guesswork out of whitetail hunting: finding what kinds of deer live where so you don’t waste time hunting where there are no intended quarries. To be productive, scouting should be thorough. If thorough enough, however, while scouting you will alarm many deer in your hunting area, most of which will temporarily abandon their home ranges. Does with young, yearlings and fawns, will likely be back in their accustomed home ranges within 1–3 days unless other hunters scout in the same area after you scouted. Upon returning, these does, yearlings and fawns will be extra alert up to 4 days. Upon being alarmed enough by you while scouting to make them raise their tails, snort and/or bound away at top speed, mature bucks (2-1/2 years of age or older) are likely to remain off range 1–2 weeks. Being experienced at surviving hunting seasons, upon returning, they will remain extra alert a week or more. Ideally, to ensure the whitetails of your hunting area will be doing predictable things at predictable sites (feeding areas or certain deer trails, for example) during predictable time periods (making them most vulnerable to hunting), you should complete your preseason scouting, stand site selections and other field preparations at least two weeks before a hunting season begins.
Scouting a day or two before the opener is one of the most ruinous things you can do. Afterwards, like one neighboring hunter said a few years ago, you’ll likely end up saying, “Hunting was disappointing. We didn’t see near as many deer in our hunting area as we saw while scouting the day before the opener.” If you can’t scout early enough, you’d be better off skipping preseason scouting all together.