Well last night I want to thank Alenxgot the plant, who was giving it out during the dinner party. I might need to water and transfer it to a better pot. When I got home I let Riker and Lei sniff out the plant, and a few mintues later they got this akward effect. It weird as they say, but for Riker it had an effect on him like he's on drugs. I took some of photos of them together, and Lei was well behaved.
After watering the plant left it in a higher place, where no cat can reach it. Honestly when I came to the servie area I just saw Riker still staring on the plant. It must have a huge effect on him, that he's been sitting near where I have place the catnip. I guess for us humans the marijuana is our catnip, and the same goes to our cats.
