Both emu have now decided they like snails, and can swallow them whole up until about 1/2 an inch shell size. Larger ones are usually acceptable if I just crack them enough to make them swallow-able ... but if they're crushed, or pecked at too many times before swallowing, they start to produce bitter foam and become "Yucky for Emu". They went through about 70 snails between them one day, mostly around a half inch size.
Those snails disappear in the digestive system ... they can pig out on snails and no signs of them come out the other end. Also, weighing the emu, the roughly equivalent weight of snails eaten comes out as extra growth on the emu the next day ... apparently snail protein is very efficient to digest. I think that is probably good for them as calcium is supposed to keep their legs strong.
Slugs, Snails, Slaters, Worms, Crickets etc have all been pronounced "Yummy for Emu" and appear to have a more or less 1:1 weight gain conversion!! The sight of any of these creepy-crawlies is so exciting and they snap gobble down so fast it seems obvious Emu naturally love to eat any small bits of animal type protein they can. They take to these much faster than most chickens I've hand raised.
On searching, I have now found information that as adults they eat mice, small lizards, and even small eels etc.
The biggest concern is that they like the look of Bumble bees!! Yikes!! I don't need poor little Drogo or Rhaegar pecking a bumble bee and getting stung ... there is so much venom in one of those great lumbering giants of the bee world. Poor little Emu's whole head would probably swell up ...
The next biggest concern is walking them past places that may or may not contain nuts, bolts, screws, nails, or other nasty swallow-able objects ... they clearly have no sense in that regard, and they gulp so quickly. One of them (I don't know which he moved too fast) may have swallowed a piece of broken pottery off the drive of approximately 3/4 inch in size. He may not have too. I don't know for certain. I'm happy for them to eat little stones for their digestion, but the piece of china bothers me ... I hope he didn't really, it could be sharp.
For exercise I'm taking them with me around the farm every day (if not raining) to check the sheep goats cows etc. This takes a 1km or more roundabout route ... but as the Emu run circles around me they get a lot more. We run circle races around some nice flat paddocks which they love to do, walk up and down hills, and take regular stops in Emu-Yummy places to graze.
We take orbits around the garden/orchard area to graze, snack on yellow mustard flowers, and hunt snails out of the brussels sprouts.
Today I have totally worn them out, they have come home and crashed asleep on the floor ... one is lying flat, the other is a Tripod Emu right now.
Exercise also seems to promote faster growth that day!
I don't know what species your Little Yellow Flowers are but I have a lot of Mustard (Cover crop) flowering in the garden right now and started giving them those flowers early on. They love those little yellow flowers ... but now when I offer them for instance a Dandilion or a Puha flower they grap it in excitement, then spit it out in disgust ... not the right little yellow flowers ... even broccoli and radish, closely related to mustard, are not acceptable! Mustard flowers are the ONLY little yellow flowers for these guys apparently ...
