The great garlic mystery

I didn't have high hopes for the spring sown crop of garlic as the winter sown lot was so poor but I had thought we might get slightly better than this. I reckon I usually get more garlic in 4 decent bulbs than I have in the whole crop this year.

Of the ones that did grow only 3 are of decent size and, as with the first harvest, most are round fat single cloves about the size of a marble. However the strangest thing is that at least 2 thirds of both crops have just vanished into thin air.

Could they have just rotted away or is there a mysterious garlic eating creature on the prowl?