nest disappeared

[Kayleigh]

The other day I had a nest in a spiky 15ft high berberis today there is no trace of it..
The nest was small could have been a blackbirds nest the sparrows have been raiding my hanging basket for nest material.
I am not sure if this nest was new or old as I dont often go down the bottom of the garden.
Would the sparrows raid a nest for material for their own nest building..
I put some dog hair in a blue-tit box once and the blue-tits went in got the hair and took it to build their nest.
But never known a bird raid another nest for material.
I dont think cats can get up there as the spikes are lethal on that bush.