IR, Audio and earth batteries discussion

[ocpaul20]

This is not a technical idea but something I think we may have to bear in mind when we discuss technical items.

I am an armchair yowie hunter, but from the programs I have watched (assuming that some of them and some parts of them are legit and not just completely made up) I think we may be coming to the conclusion that large bipedal apes may be able to see into the infrared and also may be able to hear frequencies above and below our own hearing ranges.

This would mean that we cannot use IR LEDs to illuminate trails because it would be for them, like floodlighting the area.
It would also mean that electronic equipment which may have oscillators, etc in it might be able to be detected (although usually the oscillators are very high frequencies). I am wondering if they can hear some parts of the electronics ?

I say all this because the equipment put out in these programs is often detected and destroyed or torn down from where it has been placed. Although, this might be just because of the human smell rather than the IR or electronics being detected.

I have also wondered about earth batteries or tree batteries and whether they would produce enough oomph to power a camera or small raspberry pi or arduino perhaps? I know that the old time telegraph lines used to generate a very high voltage, so maybe we can use something like this to replace a battery in the setup? If that worked, it would give us unlimited powering of equipment out in the field.