Was sitting here the other day and a thought hit me... If wards have 3 life bars, and they last for 180 seconds, they either run out after 3 minutes, or, if you hit them 3 times. Sometimes I see people put wards down and I'm only able to hit them once, so nothing happens. But what if, as a consequence of putting your ward down close, the 3 HP represented 60 seconds of the wards duration. So ward goes down, I'm not able to kill it, but I hit it once, so it now lost 60 seconds and will last for 2 minutes instead.