Some people just don’t care. I don’t understand that either, but I think the approach you took was the one that usually works out for the best. One thing I will say is that, while it may not have seemed like you made an impact at that moment, you never know what effect 10 min with a snake in the driveway may have later in life. Especially with kids, little experiences can have large effects down the road. Maybe the next time they see a snake they’ll feel a little less scared (even if they’re still somewhat scared) and slowly change their perceptions or gain an interest. Even if not, if you take that approach (explaining patiently and non-judgmentally), you’ll win some folks over in the long run.
In the game of outreach, hitting lots of singles over the years is probably more effective than the occasional home run, even though it doesn’t necessarily feel like you’ve won any major victories and you may not get many “Aha” moments that give a ton of gratification. Keep up the good work!