Q: How can I manage the slugs that come to the cat and dog food bowls on my brick patio?
A: I suppose a long term solution would be to stop leaving pet food outdoors. But if you want a quicker answer, astute listener Karen H. suggests making a food bowl platform out of copper sheet, available online from sellers of embossing supplies. Slugs and snails will not cross copper metal due to an electro-galvanic reaction with their skin. Maybe you could make a similar platform by surrounding the bowls with copper pennies, attached to the surface with hot glue.
NOTE from John D.
Re your suggestion of trying to use “copper pennies” in a ring to repel slugs. Current pennies contain very little copper — you’d have to look for pennies of older coinage for a significant copper percentage. I doubt this suggestion of yours has much chance of success.
NOTE from Ron O.
Last year we had flowers in planters hanging from our deck rail, in an effort to defeat the slugs I made 6 inch circles out of many strands of copper wire woven to form the circles, and put one circle around each plant. I watched with interest as the slugs just crawled along and over the copper rings, so in my opinion copper does NOT stop slugs getting at your plants and eating them.