Well, they are not all 17, it's just that from everything I have read and from personal contacts ( I know people who work in Dover, in Kent education and social services etc) I know that 90%+ of the unaccompanied minors are 16+, are male, and hope to join family members, or have been sent to bring family members over at a later date, they aren't tiny orphans. They are not all from Syria or war torn countries, many are from Africa, Pakistan etc . They will have had opportunities to claim asylum along the route, but choose not to do so. They don't try to come here because of the EU, France only agreed to the border in Calais because of the EU, if we leave the EU presumably the French will just put them all on boats and we'll have refugee camps in Dover or the Isle of Wight.