Yes, yes, and yes (squirrels)...though they typically do not eat daffodils (I hear).

If you're in a warm winter zone and have Oriental lily bulbs they will definately decrease. (Gophers love all lilies.) I apologize --- my head must have been on another post that mentioned lilies??

Species daffodils can reseed, the larger flowered cultivars much less so. Only species tulips are likely to reseed. For garden cultivars it is very unlikely. In any case, if the bed is new self seeded bulbs will not have had time to reach flowering size.

The most probable reason for your stray bulbs is that they were relocated by wildlife or that there were tiny bulbs in the potting mix or compost you used.

I doubt they are there due to seed, as they would need some years to reach flowering size. So it sounds like squirrels.

We don't have squirrels but they sure look cheeky enough to gather bulbs from various places and plant them in others.

If the squirrels look genuinely perplexed at our accusations, then another possibility is that the bulbs were already present in the mix you brought in.