A basic example is a coin toss - if you throw heads the first time, the next time you toss the coin you could get heads or tails with 50/50 chance. If you get heads 100 times in a row, the next toss could be equally heads or tails, no exceptions - the past does not determine the future. The present state is that you have a coin, and it has heads and tails with equal weighting, no other information can influence to future toss of the coin (assuming a fair toss and that the coin is equally balanced)
After about 15 minutes, it did finally pick a point that was through the safe passage, but after getting out of the bleach enclosure, it decided that it was going the wrong way, and went back into the enclosure to test other points. The ant did not discern that the bleach barrier was continous, except for the back part.