RAPPLEBY2000 said:
2. we have 5 senses and when in an unusual enviroment i reakon, they are telling us stuff we just can't decipher.
Ah the old school myth of only 5 senses, I don't mean that in a "we have otherworldly senses" more along the lines of we are taught that it's five but that's it's actually much more than that. Nice quick article at this kink
http://en.wikipedia.org/wiki/Sense to show what I mean.
Another thing to bear in mind ( pun not intended ) is that consciousness is entirely a constructed thing, the whole of our conscious thinking is actually us predicting the "now" situation from information we recieved fractions of a second ago and creating our "now" from that information, we're so good at it that we don't notice we're doing it, eg 25 frames per second is good enough to fool us into thinking that a series of statice video images is a continuiosly moving thing, whereas in reality our brains are filling in the blanks with what it expects given what it thinks is the situation and what it ( that is our individual minds) believe's is possible.
If during our wanderings we find our body responding to something like an increased amount of carbon dioxide, in a local area, we may not consciously percieve that as an increase in CO2 but we may notice an increase in our breathing rate and some physilogocal changes in us that are unacoutable, from a direct point of view of sensing the carbon dioxide, and fill it in with some other possibility. Unaccounted for changes are also likely to make us more alert to trying to pick out changes we can account for, eg maybe pay more attention to hearing, in the case of something like CO2 which will alter out resperation we may note that we have unacounted for phyical feelings. Also we may tend to check for them if we've noticed we're responding to something and we don't know what it is. Slight aside, did anyone else notice the different feeling they had in the big toes of their feet before they read this sentence

Those that have since noticed they have, probably already did uncosciously but unless it was an important difference it's unlikey to have been brought to thier conscious attention.
Or on a slightly more bushcrafty note, how many people get a more relaxed nights sleep hammocking under 2 Lime trees in Spring? Now would that be beccause of some spirit of the Lime wood or the mildly relaxing effect of limeflowers and pollen?
I can't think of a creepy tree at the moment but it may be interesting if people stated what typre of plants in the woods they find creepy.