Yes we have an instinct to eat, But some people will choose not to eat when hungry...anorexics are one example...people on hunger strikes are another. This shows that humans are not BOUND by instinct in the way other animals are.
Many people , including me, have seen a pet refusing to eat, sometimes to death, because its master was dead or gone. We can interpret this in different ways, and I'm not the kind to "humanize" cat or dogs, but it seems to me these animals also have the ability to depart from their instincts.
The instinct to care for offspring is very strong amongst all animals...except for humans who readily will kill their offspring ie abortion. Or they will neglect them and not care for them properly.
Lions sometimes kill their own offspring to get the attention of the mother again. Some sort of jealousy, to give some "human" meaning to this behaviour.
Even when it comes to Fight or flight we present a non instinctual behavior. Animals will hear a noise and run, but humans are more inclined to get closer & investigate. When a volcano erupts for example we see the smoke rising and want a front row seat...many people have died because they did not flee in time. Unlike animals who sense the danger and take to flight at the first signs of activity.
Some situations can make us ask questions about our instincts, it's true. The last well known and spectacular example that comes to my mind is the asian tsunami that costed so many lives. A large part of the people who were on the beaches fled. Some stayed watching before dying, etc.
Humans are simply more intelligent than girafes, birds or cows. They have learned what fire is. That's what allows us to take risks, even if we don't have an estimation of the risks that is precise enough. Maybe some people are unaware of the dangers that can come from the sea. I can recognize a fire, i can put a name on it. A bird can't do that.
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