Washer jets not working. Why ?

I was on my way back from work and my window washers suddenly stopped working. they were working a few days ago and the headlight washers still work perfectly so why don't the bonnet ones ? The rear doesn't work either.

There is no blockage as far as I can tell and I have prayed de-icer and used a needle to prod the holes just in case.

Has anyone had this before. I'm thinking the motor (I'm guessing there's a second one for the headlights) or a tube fallen off.

If anyone could spread some light on the subject it would be most appreciated.
 
I can hear the headlight washers but no when the lights are off I cant hear anything. Bonnet up head inside and still no sound.
 
Thanks for the replies. they just started to work again magically. must have been some frozen water in the nozzles I reckon.