I got something sprung on me and need to figure this out.  One of my players is a ranger who doesn't like magic.  He rarely ever uses any ranger spells available to him.  However, he just pulled something on me that I am not prepared for.  

They are about to crash a secret meeting in disguise.  They haven't given me their plan but I highly doubt this will go well and they will probably have to kill a bunch of the folk there (these are bad guys, so yeah no problem there).  I want them to get a lot of intel out of this but I don't want them to get EVERYTHING.  Given the nature of the site and the fact that I doubt they will have a plan to capture everyone (if they do and it works I will just tip my cap and give it to them), I expect I can have at least one of the targets escape. They don't know who it is and it is kind of a big reveal for later.  But as I said, him slipping out with maybe only a clue or two left behind would be ideal.

The problem?  As we ended the last session outside and they counted the horses to see how many were inside meeting, my ranger suddenly says... "Ooh.  I can just Speak With Animals.  I can ask all the horses who their owners are.  That way we will have a list of everyone involved in this secret society."

And I am not sure what to do about this.  What would a horse know?  It would know where it lives, for sure, but could it communicate that?  Is it, "I live in a stables," or is it, "I live at the lovely stables of the VanComte estate where I am tended to by many groomers and get lots of carrots," or something in between?  I would much prefer not to give them much from the horses (heck... they might be able to just skip the meeting infiltration if the horses give them enough intel) but at the same time this seems like a quasi-good idea that I didn't account for and I don't want to just shout, "nope!" because the players outflanked me.

This is entirely up to you :)

However, a Riding horse or a warhorse has an int of 2 compared to a dog or cat with an int of 3. On the other hand, horses can be pretty smart creatures.

Here are some possibilities -

- does a horse know their own name? Likely - it probably knows what other folks call it.

- if it has a regular rider or owner - it would probably know if they are friendly or mean, it probably knows what they generally look like, whether they are big or small, maybe hair color. The horse might or might not know what other creatures call its rider. It likely won't know the whole name - the horse might only know that other people call its rider "ma'am", "sir", "Joe", "jerk" or something less printable.

- The horse would know whether it likes or fears its rider.

- the horse may be able to pass along information about the creatures that take care of it, those who feed it and keep it happy. It may not remember that much about its rider if it isn't ridden that often by them.

- the horse may remember how to get home depending on how far it has come and how often it has taken this route. It certainly could not tell someone where it lives but might be able to show them by being encouraged to go there.

If I was DMing this situation, I would give the horse some useful but mostly humorous information about trivialities and things that would interest a horse mixed in with a few bits of other information.

So .. what can the players learn here? Roughly the number of folks who arrived on the horses - did anyone ride double? However, there may be a good chance that not everyone actually came by horse. Varying rough descriptions of maybe 1/2 to 3/4 of the attendees (not all horses will have that great a memory or care about their rider), possibly one or two actual partial names (likely first names) plus other terms that others use to refer to their rider when the horse is around. The names of the horses, what their favorite food is ... the horses may be more inclined to talk if the Ranger feeds them too ... a rough idea of which direction the horse took to get here and maybe some really rough descriptions of what the stable they usually live in looks like. Do they live in a run down stable or a nice clean one. Are there lots of stable hands or none. Do they have a field to run around in or just a road outside the door filled with city smells?

As DM, it is all up to you but horses should give a bit of information, some comic relief but they won't solve an adventure unless you want them to ...

When my Ranger player has asked questions like this with Speak With Animals, I have tried to emphasize that although she can talk to the animal, it doesn't always understand things the way humans do. For example, as anyone who has ever had a cat will tell you, if you could speak with a cat and tried to ask it who its owner is, the cat would have no idea what you are talking about - the cat thinks IT is the owner and WE are its servants. It may think we are very good servants, but to a cat, we exist to provide it with food, play with it, clean up its droppings, and be a snuggle buddy when IT feels like it. Ask a cat who owns it and the cat will say "No one."

Similarly, a horse would speak to the ranger in neighs and whinnies, and also with ear flicks since those communicate information to horses, and the spell would allow the ranger to interpret. What the horse could communicate would be HORSE thoughts, much like a cat would communicate CAT thoughts. Would horse thoughts include ownership? Who would the horse think owns it? The guy who rides it? Or the one who rubs it down after a ride and mucks out its stables? Humans master herd animals because we replace, in their minds, the herd leader... so more likely the horse thinks its "owner" is its herd leader.

So a horse would communicate ideas like, "I live in that shelter over there" (if it is nearby). Or "The man who smells like clover and brings me apples is my herd leader." Does that mean the owner or the stable-hand? You'd have to ask more questions of the horse... i.e., "Does your herd leader ever ride on your back?" Then yes or no would get you further. 

For example, when I do this, most animals do not strongly distinguish among humanoid races... they call them "two legs" and consider them all to be pretty similar. Animals in my world were able to convey the difference between lizard folk and humans by expressing they were "two legs with a tail and scales" but they wouldn't be able to express the concrete idea of "lizard folk" because animals wouldn't think that way.

I think Speak With Animals can be a great tool when used properly, but it doesn't give the animal the sort of comprehension a human would have. For example, when wolves were getting ready to attack the party and the Ranger cast it, and asked the wolves why they were going to attack, the wolves said "We are hungry. You are food." That's it... simple expression. You can't get "Well, my friend, the hunting has been rather poor the last 17 days up in the hills to the southwest, and we have traveled these 12 miles and now we want some dinner." Wolves don't know what a week is, have no human concept of time, and would not know what a mile was.

Speak With Animals lets you understand the animal's noises and body language (if that is part of the communication) but it doesn't give the animals human levels of reasoning. They can only answer the way an animal would think. So you need to so some RPing and put yourself into the mind of a horse and consider, what would a horse think and how would it answer this question? Again even the concept of an "owner" would probably be strange to a horse, since "ownership" requires an understanding of property, which is not something a horse would know anything about.

I guess it helps that both I, and my ranger player, are animal behaviorists so she completely understands where I am coming from when I do this....

You have to be careful about speak with animals because it's easy to make it either too useful or too useless; if you take animal intelligence literally it's sort of a spell that does nothing. In this particular case:

• A horse would know what its regular rider looks, smells, and sounds like, so it could give a description, or in a police lineup, identify its rider (though for a high status person who uses stablehands, the horse might not actually have much interaction with its owner). It would probably also remember its most recent rider. There's no strong reason to think it associates a name with that person, however.
• A horse would know where its home is. This would allow identifying people by their houses. Actually parsing its description of where that home is might be challenging, because it's not going to know place or street names.
• There's no guarantee that the horses in the stable are a perfect match for the people meeting inside -- some horses might be unrelated, some people might have arrived by means other than horses.
• There's a good chance someone is keeping an eye on the horses and will notice weird people talking to them.

A horse would know what its regular rider looks, smells, and sounds like, so it could give a description

I agree with this but to the OP, keep in mind that horses do not have red cones, so they cannot see red color. They do see color but in a more muted way than we do -- in the old days, if you ever saw a CRT monitor that had a malfunctioning "red gun", everything looks like shades of aqua, with maybe some more blue or green or yellow sections mixed in.

A horse would be able to describe smell and sound just fine, I think, but the question is how we as humans interpret what it is saying. That is, horses can smell and hear things we can't, so if a horse said, for instance, "my human smells like clover" and it is a VERY subtle smell, we might not be able to smell what it smells.

, or in a police lineup, identify its rider (though for a high status person who uses stablehands, the horse might not actually have much interaction with its owner).

Yes, I think a horse could pick someone out of a line-up as "my regular rider" or "the guy who cleans out my straw".

There's no strong reason to think it associates a name with that person, however.

Exactly. Animals often "know their own name" in the sense that they associate a series of short human sounds (usually 2-4 syllables) as their human calling them. Even birds such as ravens have been shown to do this. Whether they understand the concept of a name, though, is hard to tell. When I called "Sandy!" and my cat came running, did he know his name was Sandy? Or did he just know to come running when he heard that sounds. Again, the concept of individual identity is probably different for animals -- especially a herd animal like a horse, for whom behaviorally, the individual tends to be subordinate to the group (vs. humans, for whom individuality is often everything to us).

Some animals do seem to have "names" for each other according to recent research. (Whales apparently have unique calls that signal each other individually.) Bbut this is usually limited to chimps and whales/dolphins. Not something like a horse.

Quote from Pantagruel666 >>

You have to be careful about speak with animals because it's easy to make it either too useful or too useless; if you take animal intelligence literally it's sort of a spell that does nothing. In this particular case:

• A horse would know what its regular rider looks, smells, and sounds like, so it could give a description, or in a police lineup, identify its rider (though for a high status person who uses stablehands, the horse might not actually have much interaction with its owner). It would probably also remember its most recent rider. There's no strong reason to think it associates a name with that person, however.
• A horse would know where its home is. This would allow identifying people by their houses. Actually parsing its description of where that home is might be challenging, because it's not going to know place or street names.
• There's no guarantee that the horses in the stable are a perfect match for the people meeting inside -- some horses might be unrelated, some people might have arrived by means other than horses.
• There's a good chance someone is keeping an eye on the horses and will notice weird people talking to them.

And I think we have a winner. 

On the rare occasions he has used this spell in the past, I have mostly used it for comic relief.  He is usually trying to talk to cats or dogs to get "references" on NPCs (he believes animals are a great judge of character.  I disagree so he usually gets nothing but funny dog thoughts).  This is a scenario where I think it makes sense to give them something, however.

I will give him time to ask 3 questions (one horse has a fancy, expensive saddle so I expect they will question that horse, but who knows?) and then one of the cultists will interrupt.  At that point they will either have to dive in to their infiltration plan, or blow their cover.

I do appreciate all the responses.  This is yet another thing where I never considered it (RPing the animals as animals) and would do things a little differently on the next campaign. 

Thanks, all.

If you want to do things differently, you don't need to wait until "next campaign." A good GM makes mid-course corrections rather than letting something keep being played in a way that the GM no longer agrees with.