From body sensors to water coolers, here's how companies are watching how full their offices are

• Employers have unique ways of telling how full their offices are.
• There's more interest now that more bosses are calling their workers back to the office.
• From office-style radar to measuring the flavored water, the metrics are revealing.

As more companies push return-to-office mandates, there are under-the-radar ways they're measuring how many people are showing up — and how workers are using the space.

Some employers are turning to sensors that can tell when a person is sitting at a desk or using a conference room.