My bichir tank is inhabitate from that kind of snail:
They are nocturnal and hide during the day. They dig themself into the substrate and only show up at night. They don´t eat any plants in the tank so far.
Doesnt appear they do. Sounds like they multiply prolifically so keep that in mind. If they are what I think they are in the same family as malaysian trumpets. I started with a 100 mts and ended up with thousands......If I had them again I would pull adults out regularly
probably not to your ornate. it likely came in on some of your live plants and an overpopulation may mean trouble for your garden. boil some cucumber and leave it overnight. check in the morning to see how bad the problem really is