Thank you both, Mick and Miranda, for your suggestions. You're right. For such stupid animals they sure come up with some amazingly clever manoeuvers.
In response:
Miranda--TOP ENTRANCE The birds already hang out on the roof (I think they think it's the outhouse). An opening there would facilitate entry, I'm afraid. Also, this is the tropics--our torrential rains would leak through a roof opening. HINGED DOOR: Tried. CATS are not happy with it. They want a ledge to stand on. I don't want a ledge because the peeps fly in through the lattice if there's something to stand on. FEED CHICKENS: That sounds REALLY GOOD! What would chickens like better than cat kibble? They have access to all sorts of bugs, etc. These feeding stations are all in parks: palm trees, bush, beaches, tourists, ground cover, geckos, BUGS BUGS BUGS.... They like kibble so much they will rush me, peck at my legs (STUPID--like that's going to convince me to feed them?). The guy feeding last summer didn't use a garbage bag, just dumped old/ant-covered/moldy/whatever food on the ground and the chickens became addicted. (He's no longer with us...)
Mick--TUNNEL Interesting concept. I'll get out my graph paper and see what I can do. Will get back to you. FINS "discomfort from hitting wings on fins". Do you think if I hung something hard, like dowels or paint stir sticks, in place of soft mop strings and sail cloth, it might discourage them? Maybe danglies should be HARD? Does noise bug them? Like clatter from sticks knocking together? Maybe I should have pointed out that these are HIGHLY inbred birds who don't even know to crow at dawn. They crow all day AND all night. I'm not sure how delicate their sensibilities are.
CHICKEN QUESTION: Do chickens manipulate with their feet like parrots, sun conures, parakeets? Maybe to hang upside down on the opening of the hole and pull themselves in? Or fly high enough to boost themselves in with their feet?