I get these block when my daughter be 5 month old and she love they right away . she be now 9 month and she still love they . she seem to like the crinkly block better than the rattly\/jingly block , but they all have something different that attract she to each of they . I wish there be more than just 4 of these block ! we always bring at least one block with we when we go out in the car . wash machine have yet to destroy they , I just put they in a mesh bag on the gentle cycle .