I have a way with animals. I've always been so happy to be around animals, whether it be pets like dogs or cats, yard animals, or animals at an outdoor park or the zoo. I've lived in a lot of places where I've been able to form strong relationships with stray cats, and whenever I'd go outside for a walk, I'd notice squirrels, birds, and rabbits weren't afraid of me like they were of other people. For a while I thought it was because I was a total freak, but then I realized it's because I act different than most people around animals who are skittish.
In order to get animals to get close to you, you have to be very patient and quiet. I've found that when I first see an animal, they look at me from a distance to see what I will do and observe my behavior for a while before deciding what they will do.
A lot of cats that I've met aren't very friendly at first, even if they are naturally affectionate and want to be around humans. When cats are kittens, they need to be socialized with humans before they are 14 weeks old, with the most important socialization time being between two and seven weeks. If kittens are not socialized within these time frames, I've noticed that they are more reluctant to greet humans and other animals and can have a variety of negative behaviors.
What I do to befriend cats, whether they be house cats or stray cats, is if I am inside of a house, make sure I'm not in a place where they feel threatened. If they sit in a specific area where they feel safe (with insecure cats, this is usually in an elevated area), I make sure I sit where they can see me at a distance. What I've found is that once they observe you for a while and see that you are "safe", they will usually decide to try and get closer to investigate.
Their "investigations" usually involve watching from a distance on the ground, inching closer (don't make any sudden movements or talk loudly when they are doing this or they will run back to a place where they feel safe and the whole process will start over again), then running past you quickly. They seem to continue this running back and forth past you quickly until they believe you are not an imminent threat. Then, they will inch towards you and stop at your feet, being very watchful. This isn't a time to pet them because they are still investigating you. Let them sniff you and check you out. Once in a while, you'll get cats who feel threatened at this point for whatever reason and they may try to scratch you or pee on you. Just kind of watch them to make sure they aren't looking at you with their ears laid back or backing up to you, and you should be fine.
After this point of sniffing you, I've found that they will try to mark you in some way. Usually this means they will mark your shoes with their scent glands located on their jaws, but some may rub their bodies on your lower legs by walking back and forth in a figure eight. It is at this point where they will usually "tell" you they are ready for you to pet them and be friends. Sometimes they will meow and look at you directly. At this point, their ears are usually pointed up and they are sitting down looking up at you. Sometimes they stand while rubbing on your legs, but their tails aren't switching back and forth quickly. I've noticed that if their tails are moving back and forth quickly, they might bite or scratch you because they are agitated.
With stray cats, I've noticed that they have similar behaviors to house cats as far as observing you and being watchful of your behaviors, but it takes longer and you have to have more patience. I've noticed that if you sit outside in a chair and don't move, they are more likely to come up to you than if you are on a walk. Another thing I've noticed with strays is that if they see you have befriended another stray, they are much more likely to come up and greet you within their own territory than if you hadn't befriended another stray.
In one neighborhood I lived in, I befriended six stray cats and one neighbor's house cat, and they all had their own territories, but they would greet me and follow me within their territories. Some cats got along better with each other, so they could tolerate being within a few feet of each other as long as I was there. What's strange is that they didn't really seem to want food or water, just company, so keep that in mind if you want to befriend strays. It probably doesn't need to be said, but just in case, always wash you hands after you pet strays because you don't know if they carry diseases.
Dogs can be a lot easier to befriend than cats just because at least where I've lived, most dogs live in homes and have been socialized. Just like cats, dogs also need to be socialized as puppies in a certain time span in order to be well-adjusted and friendly towards humans and other animals. Some breeds do have personalities where they are just naturally more protective towards their family, so despite socialization, they may still be somewhat unfriendly at first.
My dog is a German Shepherd and Australian Shepherd (Blue Heeler) mix, and he is very much a one or two person dog. He is very affectionate, playful, and talkative, but he is very guarded when meeting new people. Usually if I introduce him to someone and they don't make sudden movements, talk quietly, and wait for him to "investigate" (just like cats), he will decide they are okay and acts just like he does around my husband and I, just a little more excited.
I've found that most skittish dogs or guarded dogs are similar in that way. I tend to follow the same steps I do when I first meet cats and found these steps to be successful. I have found that dogs seem to take less time to decide that I am "okay", and I believe that's because dogs seem to be more attached to humans than cats are (in general - I know there are exceptions to any animal), so they think if their alpha thinks someone is okay, they do too.
As far as stray dogs, I don't have any advice because I've actually never met one. I've found lost dogs, taken them home, called the number on their tags or taken them to a local vet to see if they've been microchipped, and (thankfully) returned them to their owners. If you ever find a lost dog, usually they will have a collar on or look somewhat taken care of. Their toenails aren't usually long and their coats generally look clean. From my experience, every dog I've seen that I've picked up (one was in the middle of a busy road and another was on the side of a street, just off the curb) was friendly and immediately let me pick them up or just jumped into my car. Neither of those dogs hesitated at all, but my advice would be that if you see a dog that you think needs help, just be watchful of any guarded behaviors.
I've found that dogs will generally warn you in advance if they feel threatened by growling, showing their teeth, raising their hackles (hair behind their head/ears), and having a rigid posture. Friendly dogs have an ease to them that scared or threatened dogs do not. I wouldn't say it's good to go by their tails wagging. Even scared or threatened dogs can wag their tails before they bite you.
Yard Animals (Squirrels, Birds, Rabbits, etc.):
Yard animals like squirrels were a little bit more difficult to befriend than birds or rabbits. In order to befriend squirrels, I found that you have to be patient over a period of about a month. What I did was get some yard animal food that included corn, sunflower seeds, and peanuts. I'd get a large bag once a month, go outside every few days and shake out some more in a large cup. I would distribute it in a few areas spaced apart because I noticed that the bigger squirrels would chase away the smaller squirrels if I put all the food in one area. That way, everyone could get food and not feel threatened.
After a couple of weeks, I noticed when I would shake out the food, the squirrels would get closer to me each time. They would be watchful, just like skittish cats or dogs, but would get more bold as they began to trust that I wouldn't make sudden movements or talk loudly. If you are feeding squirrels, I found that it's best to stand in one spot and let them observe you. Eventually, after about a month, they would come right up (maybe about three feet or so) and eat near me without fear.
With birds and rabbits, I kind of think that it's just me because I don't do anything special and they have always tended to land near me or hop by me without fear. My advice with birds and rabbits is just to be quiet and observe them. Neither like sudden movements or loud talking, so if you are interested in those animals, sitting quietly in a chair would be your best bet.
1. Never just reach out and pet an animal. You wouldn't like it if a stranger came up and started rubbing your neck or back, so just think of it that way if an animal isn't friendly towards you from the beginning. Just like you might yell at or push a stranger away if they did that, an animal might meow, bark, chitter, scratch or bite you in order to tell you "hands off, buddy", their way.
2. Being quiet and not making sudden movements is the best way I've found to befriend any animal and let them know I am not going to hurt them. There are always exceptions though, so use your best judgment when you are around any animal you don't know.
3. Animals love when you talk to them once they decide you are their friend. I've never met any animal that didn't like for me to talk to them, and I've found that they become very talkative once you talk to them. I'm not talking about saying, "hey buddy, how are you?" or, "you're so cute!". I ask them questions about how their day was and once they meow, talk (my dog does this row-row-row thing like he's replying funnily enough), chirp, etc., I say something like, "oh yeah, that's pretty cool!" Trust me, I know it sounds weird, but it does work. It's like they want to try to understand what you are saying.
4. Talk to your pets. I talk to my own dog throughout the day, sometimes just like I am talking out loud, observing things, and he responds quite often. I find that if I am happy and talking a lot, he will come and sit by me and talk too (in his own weirdo way ha ha ha). My mom has some doves and whenever I visit her, I go and talk to her birds and they always pause when I am talking, then respond back. When I call her and they can hear me, they always talk back then too. I believe your animals love you and want to communicate with you, even if you can't always understand each other. I've seen it way too many times to believe otherwise.
5. Sometimes animals will come up to you and show you something they are proud of. With my dog, it's usually a squeaky ball or toy that I bought him that he wants to show me he is especially fond of. I've had cats come up to me and bring me their favorite toys. I've had neighbor's dogs bring me mail, sticks, or toys. I always tell my dog "wow, that's so cool!" kind of how you would talk to a little kid, and he always walks away happily. Any animal that has done that, I have responded in pretty much the same way. I think of it like, if they have the intelligence of a three-year-old kid, I can talk to them in that way and they should sort of understand what I am getting at. For me, it's always worked, so I think there is something to that if animals that aren't even my own respond the same way.
I hope my observations, advice, and tips have helped you. I am not an animal behaviorist, but I have spent a lot of time observing and spending time with animals, and these behaviors have worked quite well for me. If you have any questions or tips for others, please feel free to ask!