Moving water attracts birds. Great year-round. Works great summer and winter to attract birds. Helps prevent the spreading of West Nile virus by eliminating stagnant water in birdbaths. WATER WIGGLER'S™ unique agitator action creates continuous ripples in water, preventing mosquitos from laying eggs in bird baths. Easy to install. Just place in bird bath and go! No wiring and no plumbing. ATTRACT BIRDS - NOT MOSQUITOS! Operates silently on two D-cell batteries for up to two months of continual use. Operates 24 hours a day. You may use with heated bird bath in winter to agitate the water and attract more birds. 6 month warranty.