I think some do, especially elephants, dolphins and whales, apes. Maybe dogs and certain very smart birds, maybe.

Certainly. I don't think any animal would instinctually know that they need food, and need water, and need to find a mate, yet not know they exist.

Aye.. indeed and some like pitbulls know you exist but if up to them not for long.

I doubt it becauuse animals dont have souls

I would say yes.

yes...protecting ones survival is what makes as animal and not a rock LOL

They can think and perceive things in relation to themselves which is why they can be trained through their sensory feeling. But are they conscious of a "self" like man is? No

Do humans know if they exist? I certainly don't know if I exist. Descartes's reasoning that "I think, therefore I am", has been put through the grinder of philosophical / epistemological debate, and it turns out that it's only evident that "something seems to be", that there is a "thusness", but he entirely skipped a step by assuming the "I". The self is poorly defined - we really don't genuinely understand or have a good, unambiguous, generally accepted definition of it. It may not turn out to have any good scientific correlates. Invoking the self in the way his statement did is purely an example of lazy thinking and allowing an artifact of language and grammar to be seen as a real thing without justification. In general, I have yet to find anyone who really "knows" anything - although the pretense to knowledge is very common, true, epistemic certainty seems nonexistent, but not necessarily impossible. The bigger question is whether they're conscious. We don't really know if other humans are conscious - we draw our conclusions that they ARE, based on the similarity of their bodies and brains, and of their reactions to things around them. It's a theory, albeit an extremely useful and predictive one, that other humans besides ourselves are conscious (one that babies need to learn, and don't automatically believe at birth). Based on the same reasoning and evidence, we can conclude that it is a very good theory that many other, if not nearly all, animals are conscious. It's the simplest and best theory to describe their behaviour in most cases, especially in vertebrates, and the more complex invertebrates. Any consciousness is a sense of "thusness", similar to the sensation Descartes described. If the question is whether they have a CONCEPT of existence, or their own existence, then, perhaps, that may require language, and the answer may be no.

Sorry, But I thought I was a human

I've always wondered that too! haha

Yes... and some have a very strong sense of self (ego)... Apes and elephants do, for example - equally with humans if psychdynamic psychology is anything to go by... they can recognise themselves in a mirror, and don't believe that they are looking at another animal.

Yes, and they know other animals exist too!

Nope, thats why some animals mate for life, or a mother baboon will carry her dead baby around for days before finally putting it down and knowing it's over!!