I've often said that raising a squirrel is much like raising a child. The difference is that what takes place over 18 years with a child, takes place in a year or less with a squirrel. The main similarity is that squirrels, like children, have their own distinct likes and dislikes. They also have their own distinct personalities. One squirrel can be very sweet and compliant, while another can be a royal terror.
The idea of personal likes and dislikes can be seen when you raise multiple squirrels at one time over a long period of time. You observe that what one squirrel will eat, another one will not touch. It's very obvious that they have their own unique likes and dislikes, and that extends into what they will and will not eat. So, personal tastes can play a role in what foods a squirrel will eat.
One thing that is pretty universal among squirrels is the fact that they like nuts. At first thought, it doesn't seem to make sense that a squirrel would not like a Nut Square, after all, it is over 80% Pecan meal. But, in the process of making them, people put different types of fruit puree in the mix. Some use peaches, some applesauce, some strawberries and even avocado. If the fruit that is used, is not one of the favorites of the squirrel, it is possible that the scent of that fruit in that Nut Square turns them off to eating it.
Another aspect of this likes and dislikes idea is that sometimes a squirrel is overfed. When someone writes with a squirrel feeding problem, I always ask how they feed. Nine times out of ten, the people with a feeding problem provide a smorgasbord of different fruits, vegetables and nuts, and allow their squirrel to pick and choose what it wants to eat. I also ask if their squirrel is allowed to have stashes of food hidden in their cage or habitat. Scatter hoarding, ( hiding food,) is a survival instinct that has no place in a captive situation.
A squirrel that is allowed to pick and choose what it wants to eat, very often becomes a problem eater. This can be a real problem when they refuse to eat something as important as a Nut Square.
There's one more aspect of squirrel behavior that I have observed by having my blind squirrel, Lucky for over the past 8 years. And, that is, that she does not eat a Nut square everyday. There are days that she will not touch it, so, I leave in her cage. What I do notice is, that she will nibble on it, and gradually it will get eaten. I also noticed that if I withhold a Nut Square for several days, she will often accept and eat it. Being blind and inactive makes it difficult to keep her from gaining weight, so we try to keep her in a state of being hungry most of the time, and we limit the amount of food she is allowed to consume.
What this tells me is that squirrels instinctively know and will eat what their body needs. In the wild, if a squirrel is needing calcium it will raid a birds nest and eat an egg, shell and all, or chew on the bones of dead animals. They instinctively know what their body needs and will eat accordingly.
All this brings us back to the question of how to get a captive squirrel to eat healthy. The first step is to quit the smorgasbord, and do progressive feeding. Squirrels in the wild do not get 3 meals a day of unlimited quantity. They eat what they can find and take full advantage of abundant times to prepare for hard times. Survival is the name of the game for wild squirrels.
Hunger is a powerful motivator when it comes to getting a squirrel to eat what you want them to eat. This is how you do progressive feeding:
First, you clean out all food stashes in your squirrel's habitat. Starting the next morning, you serve your Nut Square. If the squirrel turns up its nose at it, that's fine, it stays in the squirrel's bowl until it gets eaten. No other food is given until the Nut Square gets eaten. When the Nut Square is eaten, you bring on the next course. If the squirrel eats it, then the next course is served. This continues until the squirrel doesn't want any more food. Nothing is left in the food bowl.
In the evening, you serve what the squirrel will eat, and nothing more. The next morning, you do the same thing. Squirrels are quick learners. It doesn't take long at all for them to make the connection that eating the Nut Square is the way to get more food.
This is an adaptation of a technique my mother used when I was growing up back in the 1950's. It was a rule for my sisters and I that we had to eat at least one bite of everything that was served for dinner, or we would have to sit at the table until we did. My mother always grew a large garden, so there was always different vegetables that were served at meal times that weren't always our favorites. But, the rule was the rule, and it seemed that I was always the one who was opposing the rule. I think my record was to hold out until 8 PM for a dinner that was served at 6PM. If I remember correctly it was over a bite of eggplant. The bottom line is, today there is no vegetable, ( except for slimy Okra,) that I don't thoroughly enjoy eating!
Apparently, squirrels are quicker learners than I was!