Depends upon who the little guys are. If you haven't seen them chomping on your plants, could be innocent bystanders.

Please post pictures.

ok so i cant figure out how to add pictures to the site, but the heads haven't been cut off but instead eaten through. it looks like the pod is still there unless you look at it from the bottem side then you see this big hole through the seed pod.

here is a link to a pic of one of the seed pods

Here is a link that might be useful: dead head

lets see if this one will work

Here is a link that might be useful: seed pods

I'm guessing here (I couldn't access the sites you offered for viewing your pics): likely villains can be caterpillars, earwigs, slugs or snails.

If you've got a pollination programme going you could cover the seed pod with a piece of pantihose tied on lightly as a hood. They stand up to the weather better than paper.

To catch the secret munchers - or at least see who's doing what - head out after dark with a torch, on a mildly damp night. What you do with the munchers is up to you. Salt baths. Or a big, heavy garden boot. The second one is guaranteed effective ;-).

If you have pets, and you find snails or slugs - be sure to get a pet-friendly snail deterrent, with a pet-proof container for serving it up to the pests, to keep them and your local wildlife safe.

With the seed pod - unless the stem has been munched through, you might find that the plant will form a sort of 'scab' over the wound and the remaining seeds continue on to ripen.

Give it a go, anyway. It would be a shame to lose a season's propagation just because of a few pesky munchers.