We have pretty good luck with the fly tags. Some years seem better than others. We use 2 tags (1 in each year). We've been following the tag rotation as shown below and take the old tags out in November when we are working the cattle.You can put the fly tag in the same ear as the ID tag. Just move over and maybe down. I have also added the fly tag to the bottom of the ID tag (punch thru the tag, not the ear). Most fly tags call for one in each ear. BUT, I don't find any fly tags that work anymore. The flies in the south seem to be resistant to all the tags. Does anyone have any success with fly tags now? If so, where are you located?