4 month old DS is a serial catnapper. I follow his wake windows which at the moment are 1.5-2.5 hours and look out for his sleepy cues but he will only ever sleep 20-45 minutes and then he’s wide awake and smiling. He will sometimes take longer naps on me but not always. He is overtired by evening so I want to try and lengthen them, or is it just something that will eventually pass and they’ll lengthen on their own? I have got an older DS who I remember doing the same but can’t recall when/how it changed. I put him down in a dark room with white noise on. Sometimes I can resettle him by shushing/patting but this is rare!