chirping sound from underneath my truck?

[HSTONKA]

I have the weirdest sound, it sounds like something is chirping under my truck when I close the driver door, and you can hear as well with all the windows down going over normal bumps in the road.....has anyone had a similar sound? , it sounds like stupid cricket or something

[lonePalm]

check for a bird nest.......lol

[h2co-pilot]

Can you hear it if you jump up and down on the truck?

You know- stand on the bumper and jump to see if it is a mobile part or a shock type of thing. Or is it only when the truck is running.