Great advice so far, thank you! I will look into that info about the stomach contents.
Which hook do you mean? These plants join in a long plastic stem that threads through a little plastic holder that is part of the suction cup. There is nothing I would call a hook. I appreciate you bringing it to my attention, and definitely would like to know if there dangerous. They also do not have a "chain" for him to get suck in, as I read a thread about someone's little one getting stuck in one of those.