trying to track down a poem

My grandmother used to tell me it 40ish years ago, all I can remember is a phrase / title - something about the mice of pikaloo (phonetic) - have tried various google searches with no joy.

If it helps, she grew up in Wales in the 20's.

Gareth

Is the poem in Welsh then, or in English?

I , as well, tried umpteen searches on google and came up unsucessful. Sorry.

Could Pikaloo = Picaloo

English (family was from South Wales) - I think I've tried googling all variants but will try again, you never know