Carlie Diameter height Silicone Slow Feed Dog Bowl - Interesting Training Feeder - The Weight loss Pet Bowl to Slow Down Fast Eaters (Pink) ~ You can visit the image link more details. (This is an affiliate link and I receive a commission for the sales)
Tried, didnt work.Heated Dog Bowl filled with sand up to about an inch from the top used as a base for chicken waterers. The warm sand keeps the water from freezing. Great idea and very economical. My chickens will be pleased!