My kitten keeps on crying the whole day and bolt out whwnevr i open the door........help.?

its been onli two days i brought it home.before this it was on the road wit three more kittens.nw it is in a empty room in my house.im taking care of all its needs bt still it keeps on cryin the whole day and bolt out wenever i open the door.....help.will it be happy if i leave it back on the road?am i trapping it?