[squarefoot]

Pairing them with PIR detection should help to also detect stationary warm objects.

[Avamander]

It's difficult to find good PIR sensors though. The commonly found cheap modules don't include a thermistor to compensate for room temperature. Finding one with analog output or continuous detection is even more difficult, most detect changes.

[stavros]

I did pair them, unfortunately PIR sensors are even worse at detecting stationary objects (less sensitive to body micromovements).