They are coming off whether the horse is turned out alone or separate. I only use the masks explicitly for the ear protection, so ones without ears wouldn't be an option. I have 3 different flymasks and they are all different brands - one was a cashel crusader and the other two I can't even remember. They all worked last year.
I have been using swat too, as a backup. I will try the halter attaching trick. So its not a sizing issue? - that was my first thought (even though they worked last year)
I think adding ears to the mask makes them easier to get off; they just seem unbalanced somehow. My guy always gets his off over his head, even when worn under a halter. I find it folder over his noseband.
I just use the old fashioned Farnam Supermask and coat his ears with either Desitin or Repel-X lotion.
If they're really dedicated to removing the flymasks, then securing the masks with a halter just results in a ripped-to-hell, unusable flymask lying on the ground! Ask me how many replacement masks I went through to learn this lesson...
"Dogs give and give and give. Cats are the gift that keeps on grifting." –Bradley Trevor Greive
I've never found a mask with ears that stayed on. The ones without ears stay on just fine. FWIW.
I just use Swat/Roll-on/War Paint in the ears.
I do this as well. My mare doesn't seem to lose hers with ears, only once in a while. My geldings stayed on for about 10 minutes every time. He now has one without ears and gets swat rubbed along his ears for repelling the flies & gnats.
"If you think nobody cares about you, try missing a couple payments..."
Personally, I think they might be irritating. They material just doesn't seem comfortable and yes, I do use them. Every year, the first few days of fly season had the boys' flymasks on the ground or being used as a tug of war toy. I got to thinking that maybe they just didn't want to wear them damn things but I wanted them to. What I did was put them on for a few minutes in their stalls for a couple of days so they could get used to wearing them again and finally when no one was rubbing their heads in their stalls with them on, I turned them out with them on and they were fine. When they finally go out with them on, they do wear them under their halters.
I think we sometimes forget that what we want isn't always what they want and we have to show them that what we want isn't so bad. I mean really, the material is uncomfortable and you can't see very well out of them. I wouldn't want to suddenly have to wear one over my eyes and ears all day when the day before I didn't have to.
Last year, we had a HUGE stinkbug problem and when I picked up a flymask to put it on, there were like 10 in one ear. I honestly didn't even think to check but one fell out when I picked it up and that's when I realized they were having a stink bug party in there. I can just imagine what would have happened if I just threw it on!