It has been my experience that the younger the snake, the better the opportunity and/or chances of conditioning it to accept a varied diet, especially when converting them from lizards to rodents. Now in the case of the longnose snake, many adults in the wild do indeed eat rodents. But those that do not perhaps had rash encounters with rodents as they not only will not accept them as food, they display that they are fearful of their scent and presence.
To scent a rodent, I use a Cuban brown anole found locally in South Florida although any lizard species should work, especially lizards located in the same locale as the longnose snake. I usually keep a lizard frozen and then heat it in hot water. The heat fosters the lizard to emit a strong scent that is easily transferable to defrosted and rinsed pinks. However the case, I have had lizard eating snakes take a pink one-second after rubbing it against a bearded dragon, so almost any lizard species should work.
And scenting a rodent with a lizard is not the only thing that conditions snakes to eat rodents. Sometime you have to reverse-scent. Reverse scenting is when you start this process of conversion by scenting their usual prey (a lizard) with the rodent. This permits the snake to become familiar with the rodent scent and not fearful of it. And the next time you feed, offer a small meal (a tiny lizard) and also leave behind a rodent scented with a lizard. And often the rodent has to be dead because in most instances, the snakes are finding their lizard prey asleep in rocks and trees, so a frailing rodent does not look natural or appealing to them. Also, leaving a live lizard and a live rodent in with the snake will rouse the snake to conditioned itself that it's feeding time, and often the snake will it both. Lately I've had a few baby vipers and Pacific Island ground boas that have refused to take to lizard and frog scented rodents. Tease feeding and assist feeding is not working and they are too small to accept both a small lizard and a small pink without risking them vomiting both, as that would too large of a meal. As such, I tried a new method and put their usual live lizard prey in a small plastic container inside the cage with the snake. And in with the snake, I placed a scented pink. So far, the anole jumping around in the container entices and enrages the snake to eat the pink, so it is working. And if it works, I say do it.
Another method to try to convert a snake to accept rodents is to dance a lizard near the snake allowing it to become roused and eager to eat. I have some newly hatched corns here that will eat lizards but displayed to more than very stubborn to accept a scented pink. I mean I have fed thousands of baby corns and never met a one that would not take scented until I met these ones. These were unfortunately starved for two months without food with someone else who did not try another method. As such, I dance a defrosted lizard near them and they get alert and active to eat. And when they are alert and ready to take the lizard, I present a defrosted and wash and scented rodent on forceps. They bite and sometimes let go, but eventually they eat the rodent. I do this a few times and they are on to rodents for good.
One thing of importance is that when a snake is converted to eating rodents, it is best to offer small meals more frequently and do not wait too long before another feeding. If you go more then a week or 10 days, then you perhaps might risk going through the extra effort again of persuading the snake to accept a rodent.
A couple years ago I obtained an adult wildcaught desert glossy snake and one of it captive hatched babies. For months, perhaps a year, the mother ran like nut away from rodents or their scent. For months I tried to get it to take a scented rodent and it would not take it no matter what I did. So I tried another method - starvation. I conditioned the glossy to take a dead lizard from forceps the second I opened the lid on its cage. Essentially, the glossy associated my presence with food, the forceps with food, and the opening of its cage with feeding. Then I starved the snake for three weeks and proceeded to have an anole in the forceps and then a small dead and scented pink in another pair of forceps. I allowed it to view the lizard through the container and get very excited then took the lizard to the top of the cage and it followed. And the nano second I opened the lid, I presented the pink. The glossy bit it and took it back into the cage as it did with a lizard but spit it out. I had to do this about three times and it did not eat it. I eventually exited from view of the glossy and left the scented pink in there with the starved snake and it ate it. After doing this a few times, it now accepts live rodents.
And of course, the baby glossy was much easier to convert. It was not as fearful of humans as the mother and took scented day-old pinks after a few lizard feedings. Another hint to condition a snake for conversion to rodents is to reduce the stress of the snake by never ever handling it unless you must to clean its cage. And if you can change the water and remove poop with forceps without ever handling or touching the snake while it rests in its hide box, then you are much better off. I find that never touching a snake during the conversion process a very essential part of the process, especially with these jumpy sensitive snakes like glossy and longnose snakes.
Also, being very patient and reading a snakes body language is important. If it's a male snake we are talking about, it may be seeking a female and be off-feed. In this instance, you are wasting your time. And if the snake is stressed by seeking proper temps, a proper hide spot, or if it's during it usual brumation period or accidentally exposed to cooler than normal temps, efforts to convert it will be a waste of time. Some folks will force feed snakes to convert them to accept rodents, however I don't agree with that method as force feeding should be a last resort to save a snake's life and to administer medication. If you force feed a snake that is not hungry, you may risk the snake improperly digesting a meal, and that can lead to bacteria and parasitic problems which eventually demises the snake months later when you though all was fine with the animal.
Dan
Here is the momma glossy eating a rodent.
