According to Betteridge’s law of headlines, the answer should be no. Feeding your ants a high-protein diet seems like a great idea in order to increase your colony’s growth rate. After all, queens need protein to produce eggs and larvae need protein to grow. So more protein equals a larger colony, right?
According to this study by Dussutour and Simpson (2012), the above mentioned equation is not true at all. The researchers have used Lasius niger in their study. First, the effect of protein-to-carbohydrate ratio was determined, resulting in a reduced survival with a high-protein diet. Further experiments showed that the increased mortality was due to the increased protein intake rather than the decreased carbohydrate intake. The researcher conclude that a high-protein diet not only decreases the worker lifespan, but also reduces colony size.
So for optimal colony growth, what ratio should you feed your ants? The study showed that with a 1:5 (protein-to-carbohydrate) ratio, ants lived longest. However, lower protein diets were not included in the study. It is therefore hard to tell if you should feed your ants even less protein, but for Lasius niger you should probably not exceed the protein-to-carbohydrate ratio of 1:5.
An important sidenote to this study is that it was performed on worker ants without any brood, meaning they weren’t able to regurgitate the protein in order to transfer it to larvae. In a colony, most of the protein would not be digested by the worker ant like in this study. Further research is therefore needed to determine the effects of diet on colonies.
Implementing the results of this study for the ant keeping hobby, I would suggest that synthetic foods (such as honeydew surrogate), which force the ants a fixed intake of nutrients, should be prepared with a bit of care. Increasing the amino acid concentration in the honeydew surrogate recipe for example, would probably be a bad idea for most ant species. You should stick with the original recipe. When providing protein and carbohydrates in seperate sources, you shouldn’t worry too much though.