text: Yes they can BUT only if it is considered suitable for the age of the students, not offensive to ethnic/religious/ gender (ect.) issues as approved by the school, and safe.  If you have questions about something - like how will other react to it...it's best to consult another teacher or administrator at your school...since they would know the regs and general attitudes of the community.  IF you are using something to demonstrate that may be offensive - inform the parents before hand, and the school admin so that anyone who doesn't wish to participate can be excused; also apologize to the class at the start of the demonstration and explain why you are using this and that you aware that it might be offensive.\n\n~What I'd like to know is what you want to put up...generally for run of the mill decorations there is no set limits that say you can or can't put something up unless it's dangerous to student.  But this may just be at my schools