mine have done that to have you got different varieties

no they are or should i say were the same last year, ive another one round the side of my house the same x

If they normally grow as single heads then they:
1) were young bulbs last year and had not reached full potential (some daffodils do have several flowers per head), or
2) this year the stems are 'faciated' ie several stems have fused together as one. You will be able to tell if this is the case because rather than being round, the stems will appear to be broad and flat. I don't know exactly why this happens but all you can do is enjoy the daffodils as they are, and they do look very attractive.

wouldnt worry they look great to me ;o)

They might be volunteer seedlings pollinated by a multiflowering variety. The cup shape indicates genes from Narcissus triandrus.