My male cat socks turned four only recently. We adopted a female cat sophie a year and a bit ago. Both of them were rescues i found on the street needing a home. Sophie was 4months old when we found her. Socks was only about five to six weeks when we found him Since the good weather has started coming in we have been bringing them out on the harness and lead to enjoy the good weather. Now sophie despite her age when we got her really took to the harness training quite well and now when you pick up her harness runs too you knowing she is going out. Socks on the other hand never really developed a like to it. But as you can tell we want him to enjoy the nice weather too. Its a fight to get the harness on but once its on and hes out he loves it. Still not what my problem is just something i wonder might be causing the actual problem. Now is the problem. Socks and sophie have got on really well almost like they were brother and sister. Which when we talk to the babies we say they are. But since we started bringing them out socks seems to be rather intrigued about escaping off the harness and exploring further afield (Plans in progress to buy a jacket harness just no money right now). Now also he is suddenly hissing and spitting at his sister which is not normal for him? Is my cat been a rebellious teenager or would there be other issues?