Pheidole pallidula is a very variable species, and a little about its variability is shown here in the form of major worker heads from different localities in the Iberian Peninsula. As you can see, there are differences in shape, colour and sculpture.   Even though those specimens were collected in Catalonia, Andalusia, Murcia and Galice, the differences are not due necessarily to geographic variability. For example, different head colour can be found in different nests in the same locality, and even inside the same nest.