Iphone keeps using celluar data on home screen?

Just trying to figure out what's going on. Whenever i'm on the home screen with no apps running the celluar data indicator spins, but as soon as i open a any app it goes away. Just wondering why is the phone doing this, if anyone knows why. And if possible is there a way to stop it.

I'm not sure why either…
But if you are concerned about using data up you can go to settings> cellular > cellular data. Then you can switch it off and that will stop data usage when you don't want to use it

Also if you have an app constantly refreshing on the home screen you
Can turn off cellular data for the certain apps under the same place. Disabling data for certain apps may stop the spinning.

They won't tell you