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Id like to confirm that BTS with very bright orange eyes are males and BTS with very dark brown/green eyes are females.I have a dark brown /green eyes BTS that i tought it was a female and i bought a bright orange eyes BTS thinking it was a male for her but they dont mate only fight! Are they a couple?

If i post a pic here can you confirm that for me?

While it is true that this can be a "clue" eye color is not the be all and end all of BT sexing.

Read all of the clues on my site, and above all, look for the give away - seminal droppings.
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Craig Loose
The Blue Tongue Pages

Eye color: There is literature that suggests that male Blue-tongued Skinks have red irises, especially during the breeding season, with the females having a brownish-yellow iris. While this has proven to be true for some male specimens of T. scincoides, I have seen just as many, if not more, proven males with normal brown irises. I have also seen this trait (red irises) in Indonesian Blue-tongued Skinks (Tiliqua gigas), on a few occasions. Two of my male T. g. evanescens specimens have red eyes, but I also have a large proven female T. g gigas that also displays the trait with the reddest Eyes that I have ever seen. I have also seen this trait in one of my female T. nigrolutea specimens. Eye color can sometimes be used, in conjunction with other observations, to determine the sex of a blue-tongue. However, I do feel safe in saying that iris color alone is not a reliable method for determining the sex of a Blue-tongued Skink.

Hemipenile Swelling: Many males have hemipenile swelling at the base of the tail. A cross section of the base of the tail would appear slightly triangular in shape, while a female's tail would be more or less round. This hemipenile swelling is usually more obvious during the breeding season. However, this is still not an easy thing to notice, and it is not always consistent.

Body Structure: One common method that hobbyists have used for years is to compare Head and body sizes. Males generally have slightly larger broader heads in comparison to their more narrow bodies, while females have slighter more narrow heads and heavier bodies. While this method has been used to some degree of success with the different scincoides subspecies, it is totally unreliable with the Indonesian Blue-tongue (Tiliqua gigas). One gigas in my collection was a sure female. She was a small 12 year wild caught captive with a very narrow head and plump body. Much to my surprise, she turned out to be a he. I also have a huge 24 inch 10 year wild caught captive gigas with a huge head and jowls, and buldging red eyes. I was convinced that he was a he till he was bred by one of my males right before my eyes proving it to be a female. It has become obvious to me that this method does not always accurately indicate the sex of a given skink (especially gigas), and it is better when used in conjunction with other methods.

Hemipenile Eversion: Some people are able to manually evert the hemipenes of a male Blue-tongued Skink. Injury to the skinks reproductive organs can occur when it is done improperly, and it is a task that is best left to experienced individuals. It is also not totally reliable in that failure to evert does not always mean that the skink in question is a female since some males are able to resist eversion of their hemipenes, although many males are much more willing to cooperate with this procedure during the breeding season. For these reasons, I choose to use other methods to determine the sex of my skinks. Many male skinks will evert their hemipenes on their own just before they defecate. Some skinks such as the Tanimbar Island Blue-tongue (Tiliqua scincoides chimaera), or the Indonesian Blue tongue (Tiliqua gigas) do not generally appreciate handling, and males will often evert their henipenes right before they defecate and/or urinate on you. If you are fortunate enough to witness this pleasant surprise, you will have determined the sex of your skink.

Breeding Behaviour: Aside from actual copulation, there are many subtle differences in social interactions worth mentioning. My skinks are kept separately, and introductions are done during the breeding season. After being placed in the presence of a male, almost all females will wriggle their tail in, what I believe to be an attempt to distract the male's attention, thus providing an opportunity for escape. As of yet, I have not seen any of my males display this behaviour. When males are confronted with other males, they will both freeze for a moment after which they both simultaneously explode with aggression directed at each other. It is critical to break these fights up immediately in order to prevent any injury to the skinks.

Seminal Plugs: The presence of, or lack of, seminal plugs has proven to be one of the most reliable indicators that I have used in determining the sex of my Blue-tongued Skinks. Most Hobbyists overlook this dead-give-away because they keep their skinks on dirt, bark, gravel, or aspen bedding. The seminal plugs simply get lost in the substrate, never to be discovered by the skink's owner. I have found that when I keep my skinks on artificial turf, at least during brumation and the breeding season, the males will "drop" seminal plugs on a daily basis. These plugs are small (about the size of a bb) clearish-white slimy little blobs with tails that give them a total length of about 1-inch. They resemble small tadpoles, and are usually found in pairs. They are quite obvious on the turf, but will dry up by the end of the day, turning a yellow-brown color and withering into thin brittle twigs. At this point they are very easy to mistake for a small piece of aspen bedding or a dried up piece of cut grass. Some people confuse seminal plugs with the urates that skinks produce along with their feces. Urates are the white chalky portion of a skinks waste matter. During brumation they are produced in the absence of fecal matter, due to the fact that the skink has not taken in any food, but was still given access to water. This can be misleading, and it is important to know exactly what you are observing. Remember that urates are chalky, and they will crumble up quite easily in your fingers, while seminal plugs come in pairs and look like very small albino tadpoles.

Probing: While probing has proven to be an effective method for sexing many snakes, it is totally inconclusive and inconsistent with Blue-tongued Skinks. It is also not recommended due to the risk of damage to the skink's reproductive organs. Many Blue-tongued Skinks are inadvertently sterilized during this unnecessary procedure. So please, do not attempt to probe your Blue-tongued Skinks, it offers nothing to gain, and a lot to loose.