Mochi is a five-year-old tabby who, to his humans, spends the night asleep on the sofa. The PG10 said otherwise. Within three nights of logging, his collar had quietly drawn a second life nobody in the house knew existed — one measured in fence lines, rooftops and a 3 a.m. walk that went absolutely nowhere useful.
The 3 a.m. patrol
Every night, between roughly 2:40 and 3:15, Mochi's track lit up a tight, confident loop around the garden perimeter. Not a wander — a patrol. The breadcrumb trail hugged the fence within half a metre, paused at each corner for about twenty seconds, then completed the circuit and slipped back through the cat flap. Whoever (or whatever) he was checking for, he never told the humans.
Replaying the week, the loop was almost identical every night — same corners, same pauses, same unsent message to the local foxes. The only variation was Friday, when he added a fourth corner and stayed out eleven minutes longer. We have no explanation for Friday.
A rooftop with a view
On night four the track did something the sofa theory could not explain: it climbed. Mochi's dots climbed the neighbour's trellis, crossed onto a low roof, and sat — completely still for nine minutes — at the ridge above the street. The PG10's map turned a mystery into a sentence: he was watching the road. Probably the same road he is forbidden from visiting by day.
"I always thought he slept through the night. Turns out he's been running a small country out there. The GPS map is the only honest witness."
The neighbour's cat
The most human moment came at 4:52 on Saturday. Mochi's trail met another, unfamiliar track at the boundary wall — two sets of dots weaving, separating, meeting again, then drifting apart. A quick check next door confirmed it: the grey cat from number 14 has a nightly appointment Mochi never mentions at breakfast. Their shared "territory map" now lives, unofficially, in our phone.
The mouse that wasn't there
One night the track stopped dead in the garage corner for forty-one minutes. Forty-one. Motionless. We reviewed the log expecting a fault; instead it was a stakeout. Mochi had pinned a shadow to the wall and refused to blink first. He left at dawn, hungry and undefeated. The mouse, for the record, was not in the data.
Territory, drawn in light
Stack the week's night tracks together and a shape appears: Mochi's true territory is roughly three times the area he uses by day. The daytime map is a lazy oval around the sofa and food bowl. The night map is a jagged crown across two gardens, a roof, and a forbidden road. A GPS track logger doesn't judge — it just shows you the cat you actually live with.
- It records, it doesn't stalk. The PG10 stores the path on the device and replays it later — no live map, no geofence alarm, no "where is he right now" anxiety. Perfect for curious cats and calmer owners.
- No SIM, no monthly fee. It logs from a satellite fix alone, so there's nothing to subscribe to and nothing to lose signal.
- Light enough to forget. At 22 g on the collar, Mochi wore it for a week and never once asked for it off.
- The fun part is the replay. A week of nights becomes a story you can actually see — patrols, rooftops, and mysterious Friday corners included.
Mochi's humans started the experiment to "see where he goes." They ended it with a rooftop, a forbidden road, and a standing 4:52 appointment with the cat from number 14. The PG10 didn't find a lost cat. It found a whole second life — and made it impossible to unsee.
Also in the field: Lost 11 hours in the backcountry — a GPS navigator that found the way home