Not exactly sure if this is a true hot take, but I feel one thing all zoos REALLY need to have that most do not is a mandatory full security check upon admission to make sure there are not any questionable items entering the zoo similar to airport flights, concerts, and sports arenas. It may make entering the zoo take a bit longer but tons of stuff goes unnoticed and a zoo, as it has living animals, is certainly not the place to be sneaking darts into. Security cameras over all the exhibits is probably not a bad idea as well, but probably not as good as a security check. Some examples of banned items can be sharp or heavy metal objects (darts, knives, hammers, baseball bats, among others that may cause a threat with the chance of killing or injuring the animals if they are hit with it or swallowed in the case of smaller dangerous items), any items with sound that are a threat to the animals (airhorns, whistles, and other loud sounds to try and call over, attract, or scare away the animals), and other extremely dangerous items to the animals and their environment (drugs, cigarettes, vapes, alcohol etc.). While there may be signs that say "No Smoking" or "Do not Feed or Tamper the Animals" for example, I have seen many people of all ages abuse these rules and zoos should take full initiative to hopefully resolve this issue by installing mandatory security checks of guests' belongings to make sure nothing of risk enters the zoo. I will say that a zoo is certainly a place that should always have a security check as part of respecting the animals and the zoo.