During the period of 2007 to 2010, every two days we visited the three cattle grids on the road to the Cap of Cavalleria, where it was possible to observe the fauna that fell into the grids. The first cattle grid is the closest to es Mercadal, the second cattle grid is 300 meters from the first, and the third is a further 700 meters and is closest to the lighthouse of Cavalleria. Therefore, the distance between the first and the third is one kilometer. During this four year period we recovered 118 hedgehogs (106 alive and 12 dead), two turtles, a rabbit, a stone curlew and a snake that otherwise would have died of thirst or drowned when the grids filled with water following rain. The chance to periodically visit an area where hedgehogs are relatively abundant allowed for an accurate estimation of the density of the population in the area and to take notes of their behavior.