Napaeus barquini actively adds lichens to its shell as a camouflage.[2][3]
References
^Alonso M. R., Goodacre S. L., Emerson B. C., Ibáñez M., Hutterer R. & Groh K. (2006). "Canarian land snail diversity: conflict between anatomical and molecular data on the phylogenetic placement of five new species of Napaeus (Gastropoda, Pulmonata, Enidae)". Biological Journal of the Linnean Society89: 169-187. doi:10.1111/j.1095-8312.2006.00670.x.
^ abcAllgaier C. (2007). "Active Camouflage with Lichens in a Terrestrial Snail, Napaeus (N.) barquini Alonso and Ibáñez, 2006 (Gastropoda, Pulmonata, Enidae)". Zoological Science24(9): 869-876. doi:10.2108/zsj.24.869.