A peaceful fish that still hunts what fits in its mouth
Leopard danios are the spotted form of the zebra danio, and they behave the same way: constant motion near the surface, tight shoaling, and no interest in fighting anything. They are not shrimp hunters by temperament the way a large cichlid is. What they are is opportunistic. A danio investigates anything small that drifts or darts in front of it, and a newborn cherry shrimp is exactly the size and shape of the live food danios evolved to snap up. Adult shrimp, by contrast, are close to the danio's own body depth, quick to flick away, and simply not worth chasing. So the honest answer splits by shrimp size: adults are safe, babies are food unless the tank gives them somewhere to grow up.
Why your shrimp's life stage decides the outcome
A cherry shrimp colony lives or dies on recruitment. The adults you buy will graze algae and biofilm untroubled while the danios race overhead, and a berried female will release her young into the tank without any fuss. Those shrimplets then spend their first weeks grazing in the open on plant leaves and the substrate, which is where the danios find them. Amano shrimp and ghost shrimp sidestep the problem entirely: both arrive near adult size, amanos in particular are bold enough to hold their ground at a food wafer, and neither breeds successfully in fresh water, so there is no vulnerable generation. If your heart is set on a breeding cherry colony, expect the danios to skim off most of each generation unless cover does the protecting.
Snails are the straightforward part of this mix
Snails need no special thought here at all. A danio has no way to harm a nerite, a mystery snail, or the pest snails that arrive on plants, and it has no interest in trying. The worst interaction you will ever see is a danio stealing a sinking pellet before a mystery snail ambles over to it. Snails also suit the danio's preferred water: both do well in the cooler end of the tropical range, and a snail's steady grazing handles the algae films that fast-fed danio tanks tend to grow. Ramshorn and bladder snail populations will actually benefit from the danios, because the fish pick off the surplus food that would otherwise fuel a snail boom.
Setting the tank up so everyone keeps their place
Start with the shrimp. Give a new colony two or three weeks alone to learn the tank, start grazing the safe areas, and ideally release a first batch of young into cover they already know. Plant for the shrimp's benefit, not the danios': a dense moss patch, fine-leaved stems, or a cholla log gives shrimplets a refuge the danios cannot penetrate, and a pre-filter sponge over the intake stops babies being drawn into the filter. Keep the danio shoal at six or more, because a proper shoal is busy with its own social chasing and pays the bottom of the tank less attention. Fit a tight lid, since danios are committed jumpers and an open top will cost you fish regardless of the shrimp question.
What to watch once the danios go in
In the first days, watch where the shrimp spend their time. Adults grazing openly on leaves and glass within a week is the sign the mix has settled; a colony that vanishes into the plants and only emerges at night is telling you it feels hunted, and adding more ground cover is the fix. Count berried females and, a few weeks later, look for pinhead-sized juveniles on the moss — seeing any survivors at all means recruitment is working. Check that the danios are not monopolising every meal, scattering food so some reaches the bottom for the shrimp and snails. A shared stocking and feeding note on KinsLe Family Sharing keeps everyone feeding the same way, so the balance you set up is the balance the tank keeps.