Why are students destructive?

bad parenting...adhd ...because they can...i have a house full of teachers with the same story i have seen all my in laws spend countless dollars and time...my time included getting clrooms and boards and ignments set up copied and put together out of there own pocket because there is no funding...i am constaly sending my kids to school with donated crayons paper towels glue sticks...etc... to help.it irritates me for you that other children's parents have not taught them respect for other peoples property...i would start like my sis in law...1st a waring..2.recess-lunch detention..3 after school detention with note to parent that they will be responsible for replacing the damaged items and providing there own child's items if it continues.aslo she keeps everything not being used at the time in a locked cabinet..good luck god bless and thank you