score:6
Now we define "intelligence" and "rationality" otherwise than Aquinas and other scholastic philosophers did. In Aquinas' teaching, reason or rationality is what we usually mean by intelligence - it's the ability to induce new knowledge by reasoning based on experience we get through senses.
"Intelligence" was slightly trickier. According to Aquinas and his contemporaries, angels don't need reasoning, they just "look and see" (this is metaphorical - they are immaterial, they have no eyes to see), they simply get the knowledge. Angels have some kind of telepathy - they give or get thoughts directly, they don't need to translate it to words, images or other symbols, share the symbols, and than translate them back to thoughts. We are material and our mind is restricted by lack of telepathy and the necessity to induce our knowledge from such symbols, from communication receivable by our senses.
Still, we participate on the simple intelligence of angels somehow. We can simply know something without any previous experience, or at least it was believed in Aquinas' times we can. Examples of this kind of knowledge mostly fail to the spiritual, to God's revelation and to mysticism. Anyway, it's distinct from either normal reasoning, or from instinctive "knowledge" which is animals' ordinary way of thinking.
Another aspect of the participation on the angelic intelligence is our ability to reason knowledge which cannot be derived from material world. Aquinas says that we can derive knowledge of God's existence from our experience with material world, but our knowledge of God's triunity and other fundamental theological aspects can be derived only from God's revelation, so this knowledge is proper to intelligence even though we learned it through reasoning. We can't learn this way anything angels can know, just some basic, easy-to-learn concepts.
Animals normally know things from their senses and instinct, they have no proper reasoning. But similarly as we can participate on angels' intelligence, they can participate on our reason somehow (not on angelic intelligence - it's too abstract for them). Thus they can be "intelligent" in the modern, broad meaning of this word, not in its medieval meaning. Using tools and reaching easy conclusions based on evidence learned through senses is an example of this participation on reason; still, apes can't really understand higher mathematics (AFAIK), so they don't possess our reason fully.
Tell me if you want more evidence; I derived this post mostly from Questiones disputatae 15 and from prologue and comments to its Czech edition.