The consumption of lichens by termites is alternative to supply energy needs of the colony, which varies according to the population size. Lichens are endowed with antiherbivory compounds and, lichenivorous organisms need to develop strategies for exploiting this resource. This study evaluated the frequency of consumption and the liquen species richness exploited by \textit{Constrictotermes cyphergaster} among colonies of different sizes, as well as verified which lichen structures are consumed by termites during foraging. In the Caatinga, 15 nests of \textit{C. cyphergaster} were randomly selected: ±6L; ±12L; ± 18L; ±24L and ±30L, three replicates for each volume. Nests were monitored for eight days from 6:00 p.m. to 6:00 a.m., scoring and marking the consumption and lichens explored. Ingested lichen structures were evaluated through bioassay, with offering of stalks of three lichen species, photographed under stereomicroscope before and after consumption. Fourteen lichen species were consumed by \textit{C. cyphergaster}. There was no significant difference between species richness and frequency of lichens consumption among different nest sizes. The lichen structures consumed were: surface of the cortex, layer of algae and margin of apothecia. The medullary region and apothecia discs were not consumed. Lichens are important resource for all stages of colony development. During foraging, \textit{C. cyphergaster} discriminates between lichen structures, suggesting a mechanism to overcome the chemical arsenal of these organisms.