The ear flaps are purely aesthetic, because dirt creatures just don't have that most of the time. So I would assume that the lady sniffers find the ear flaps sexy, like the long feathers male birds of paradise have, or elk antlers.
sniffers are biologically closer to something like moles or platypuses evolutionary history wise.
very echidna like nocturnal hippos that just happen to look enough like rocks that we thought that they were extinct when really they were just endangered and sleeping.
mutually beneficial symbiotic relationship with the algae that grows on / in their shells, making it so that the sniffers can in a sense breath through their shells instead of relying solely on their lungs, and get some extra protection from pests. In return the algae gets a stable supply of nutrients like carbon, water, nitrogen, etc.
Shell algae presentation varies case by case, some have been rumored to be capable of flowering but this has yet to be proven.
Sniffer meat is really musty and unpleasant for human consumption but you can still technically eat them if you need to.
sniffers can get sick and potentially die if they lose their algae. It is advised to avoid any major shell cleaning that involves scrubbing under shell plates. AKA, ONLY WASH THE OUTSIDE OF THE SHELL. The shell's inner ridges are generally self cleaning and should be left unaltered. You can technically scrub small patches under the plates, and the animal may even enjoy it, but this is could disturb the algae so proceed within reason.
The under plates should always be at least a little bit moist. If the spaces between plates are dry you need to re-moisten your creature. A sniffer can never be too moist, so don't be afraid to let a well greened sniffer sit in a tub of room temperature water for a few days.
Sniffers have a lower body temperature than most mammals due to their slow metabolism
Sniffers can not swim or float, they walk across the water bed an climb their way out. so be sure to give your sniffer a ramp or something if you have a pond for them so they can get out to grab some food or use the bathroom, maybe cool off some if it is a bit warm out.
sniffers hibernate underground in the mud if weather gets too hot or too cold, and will refuse to get up until conditions improve.