If you have an Android phone or tablet or Wear OS watch, you can use the Android feature "Find My Device" in your gadget. Just make sure that you have a Google account, connected to mobile data or WIFI, you are visible on Google Play, your "Location" turned on and the feature "Find my Device" turned on then you are good to go.
You can check this link for more information and instructions:
You can also download third-party apps in GooglePlay Store. Apps like "Where's My Droid", "Cerberus" and "Lost Android" are some of good apps you can use.
as @jlrei said, among others, ''Find one Device'' should do good.
If you are the one losing your phone constantly, I suggest keeping it in a pocket all the time, since I barely lose my phone.
When I do not use it I put it in my pocket and is always easy to feel it when there is a moment in which I think I lost it but that is of relative short time.
I find it funny and very true that kids tend to do that.
I hope your soon figures out hes causing you trouble
you can easily use Google Gmail to search your phone. The first thing you have to do is to go to your setting and activate your location on your phone. Then, you can find your phone by making a phone call through your Gmail setting account. Your Gmail account will make ringing your phone. Also, it shows the place where the phone is located.
If the phone is lost and you are relatively certain that it HAS to be inside the house, the easiest way to find it would be to call the device with another phone. Then walk around until you hear the call song of the device.
Of course, this won't work when your phone's on silent or less effective when on vibrating. If you don't hear it anywhere, then you lost it and 3rd party app would help better. I just thought it was worth mentioning.
Keep in mind: calling is free, so long as nobody picks up. So, when you find it, don't answer the phone, it's you