Normally if there is a singular form for a group credit i use it.  But Blind Mice is almost a stage name.  The phrase tells us something about them.  Yes it requires some knowledge beyond transcribing the letters seen on screen, but the so did singularizing them.

If the blind mice were credited collectively i'd probably go with the plural.

Give me a different plural, you might get a different answer. 

I encounter this on occasion and its always annoying.  Sometimes you'll see a block of names and a bracket saying that all those actors were bank guards.  Now I appreciate the nitpicky purists, but none of those individual guys can be plural guards.  When that happens, I lean towards entering each of them individually as a bank guard.  In my opinion, the grouping of credits is a convention, but if anyone at all involved with the production was ever asked what that actor did, the response would be that the actor played a bank guard.

Now there are established plural groups that get credited and I would leave those intact.  Goldwyn girls comes to mind, off the top of my head along with any musical acts.

I should also mention that I frequenlty submit these in the plural form so I don't have to hear any whining, and then change to the singular locally.

Thanks for the responses so far & I can see where you are coming from.

If the majority want to change to the singular then the rules really should be changed as they don't currently allow for it.

PS -  Tweeter, I hadn't thought about the example I gave being one that really should be left in the plural form! 

Quoting snarbo:

Quote:
Why not submit them using a "Divider"
Divider (Group Heading Role)
actor 1
actor 2
actor 3
actor 4 a n other role
actor 5 a n other role 2

that way the divider gets the plural role name.
Dividers aren't just for "Episodes" 

Steve

each individual person needs to have a role assigned (on the same line). So that the role is correctly listed in searches.

This has been a known issue for sometime.

Quoting Forget_the_Rest:

Quote:

PS -  Tweeter, I hadn't thought about the example I gave being one that really should be left in the plural form! 

I only thought of it because it was the Blind Mice.  From a fairy tale perspective you never see one without seeing them all.  They are always a group.

Now if they were Blind Moose, then you couldn't assume they would always been together. 

(A moose once bit my sister.)

Quoting tweeter:

Quote:
True, but there are exceptions.  A group credit as "Additional Voices" i leave alone because i can't know if they did one or many.

I do the same, because most times they are doing multiple voices.
Another example I leave it as is "couple".
For example if two people are credited as "Dancing Couple", I do not change it to something else (e.g. Dancing Man/Woman).