Toddlers sleep

3 year old has been waking up in the middle of the night every night this week, she says she is scared but when we ask why she says idk or will say something like a spider bit her arm or there is a snake... this will go on multiple times a night lasting 3 or 4 hours sometimes, we go in there to reassure her everything is ok and show her around etc... doesn't help! I'm not sure if this is to get attention or if there is actually something more going on? We are exhausted and I just wanted to see if anyone has any suggestions or recommendations to help or have an idea what's going on.