I don’t think ‘going’ anywhere would be an option. If you’re in basically, most of the civilized world, and not in a very secure structure, you’re immediately fucked. I said more than 50% but I guessed that as a very conservative estimate. We don’t normally realize just how many living things are around us, mostly bugs, but also small rodents and the like. If every one of those within a significant radius of every human suddenly went berserk and wanted the humans dead, most people are not in areas where the number of attackers would permit much survival.

Those who currently live in certain desert environments, in certain cold environments, and so forth, would probably survive the first day, and then might have a hope of making it longer. But most environments in which there isn’t enough animal/bug life around to immediately kill you present serious other problems such as food supply. If you live at McMurdo Sound Antarctica, you’re probably not going to immediately be killed. But you will soon have issues feeding yourself and keeping warm.

People in Iceland or northern Norway and other similar places might have the best chances. Probably not quite enough things around to kill everyone immediately, but the environment is one in which they might be able to become self-sufficient, but in the long term I have my doubts even for them. If the bugs and animals and such are so focused on killing humans that they no longer perform their normal functions, then you’re looking at immediate and total ecological collapse. If they’re not, then the population of bugs and animals will increase in all areas other than the most extreme environments, and sooner or later what few humans survived in those extreme environments are going to have to attempt to emerge.

If humans had prep time, maybe. Assuming we could get over our normal difficulties cooperating and actually prepare for the event. There’d at least be a lot of survivors. But if it came as a surprise, suddenly someone flips a switch and the entire animal kingdom is trying to make every single one of us dead? We’re pretty much fucked.