Not coping in vet hospital??

[Carolina]

Hi all,
I've been working as a vet nurse for about 12years now. My question to you all is:
Has anyone seen when dogs start to 'bury' their food and or water bowl when it is presented to them when in a cage when being hospitalised in a vet hospital? I've witnessed dogs, mostly but not always small breeds, do this. They will use their nose to nudge the newspaper, any bedding to try to 'cover up' the bowl. The food can be kibble or more palatable food like chicken meat, their own food from home etc. The breeds, age, ailments are all very different. When their food is given to them out of the cage, most are quite happy to eat it then.
Is this what professionals call ' Displacement behaviour'? If so, what is it? Why do they do it? How can it be minimised? Is it anxiety-based?