Before trail cams...
The first trail thing I used was a timer. I don't recall the year. Anyone remember these gadgets? Been a long time ago.
I attached trip wire to other side of trail.
Gadget would record time string was tripped. No pictures, just the time. Primitive nowadays, but that's all we had.
I used mine for predator movement. Setting trip wire lower for Fox & Coon. But a Deer could also trip timer. So numbers varied and I quickly realized it wasn't too useful for my purpose. Gave it to Brother in Law, who used it for scouting Archery Deer movement, way back then.