Good luck with that. Manufacturers for the security alarm industry have been refining "motion sensors" and other "human detection" devices for decades. I put "motion sensors" in quotes because the only true motion sensor I can think of, off the top of my head, is an accelerometer; which does't lend itself to use in an alarm system.
I use the term "motion sensor" because it's part of the jargon, but those sensors actually detect the
effects of motion (shifting ambient infrared pattern, shifting frequency of microwave or ultrasound, blocked light beam, etc); and there are random environmental factors that can duplicate all those effects.
I'm restraining myself here, rather than fill up this thread with text that may not even be relevant to your situation. Trust me, I could easily write a thousand-word essay on the subject, off the top of my head, of all the environmental factors that trigger "human detection" (a.k.a. "intruder" in the alarm industry) devices when no humans are present. The bottom line is, I don't think you're going to find a true humans-only.
They've come a long way in reducing the false positives that cause false alarms, and
most users don't have problems with false alarming.
most of the time. Users who leave pets roaming freely at home when they're away are a different story. A lot of motion sensor brands advertise "pet-immune" motion sensors, but that's sales hype, as any service tech can attest. "Pet-immune" motion sensors
are far and away more pet-
tolerant than a decade ago, but as yet, nobody has developed a true pet-immune sensor.
If it happens that you're looking for sensors to detect intruders, I can probably give you some good advice on how to minimize potential false positives;
provided that you can give us more information on what you're trying to protect. Security alarm systems are all, by their nature, customized to the premises being covered. There is no "One Size Fits All."