why is my iphone randomly vibrating?

[LegacyHeath]

Hey, has anybody else experienced their iphone randomly vibrating, without any notifications showing up on the screen?

[AnakinEmory]

Yes, I've experienced that too. Often I think I'm acquiring a call or a message but there's nothing at all there.

[RonanHank]

Probably there's an app that is sending silent notifications. Have you checked your settings?

[GianniRidge]

I have checked the settings but couldn't find any apps sending silent notifications. This is exactly confusing.

[GradyStanley]

You can try resetting your notification settings. Sometimes, it solves the problem.

[SullivanLedger]

ghost vibrations could be a sign of a software program glitch. You might want to contemplate updating your working system if you haven't done that in a while.

[JackStone]

Thanx for the suggestions. I'll try them out and see if it works.