The smock mill Goliath in front of the wind farm Growind in Eemshaven in the Netherlands. A windmill is a mill that converts the energy of wind into rotational energy by means of vanes called sails or blades. Centuries ago, windmills usually were used to mill grain (gristmills), pump water (windpumps), or both.
When bat guano is harvested, it is in a powdered form. Plants that can benefit from the use of bat guano fertilizer include vegetables, herbs, ornamentals, and fruit and nut trees.
Rocks stained with guano from sea birds. Bat excrement may be referred to as guano. Bat guano also has a long agricultural and economic history in Cuba. Pelican feces can be included as a type of guano, a fertilizer made from bird droppings.