Termite Foraging Behaviour

The latest research into termite foraging behaviour looks into the role of each caste and answers questions about preferential food sources and transportation methods. 

Latest termite foraging research

Carbon dioxide attracts termites

Researchers in the US have taken a closer look at the role of carbon dioxide in the attraction of termites to food sources, using Reticulitermes flavipes as the model.1 The researchers assessed the impact of wood mulch, extracts of wood mulch, the presence of workers and carbon dioxide on foraging behaviour. The results demonstrated that foraging R. flavipes workers were attracted to rotting wood mulch, whether alone or in combination with worker termites. From the experimental design it could be concluded that this was attraction from a distance rather than having an arrestant effect at the feeding site.

Trials were carried out to determine what volatiles were driving the attraction. Hexane extracts of the wood mulch had some attractant effect but significantly less than the wood mulch itself. Water extracts proved no more attractive than the control. However, removal of carbon dioxide from the chambers of wood mulch, and wood mulch plus workers, resulted in the loss of the attraction response. Furthermore, the researchers established that carbon dioxide alone was sufficient to elicit the same level of attraction as wood mulch and wood mulch plus workers. Therefore, they concluded that carbon dioxide was both necessary and sufficient to explain the orientation to rotting wood mulch. The authors did note that this was an air-mediated study, rather than assessing attraction within soil, and therefore they could not exclude the impact of other factors such as soil moisture and water-borne cues in attraction to food sources in the field.


Fungal extract acts as an arrestant

Having previously established that Coptotermes formosanus workers preferred to stay on filter paper dosed with ethyl 2,4-dioxovalerate, a metabolite of the soil fungus Trichoderma virens, the researchers further investigated its effect on aggregation and tunnelling and whether it could improve the efficacy of soil treatments.2 In choice studies, termites spent more time in sand treated with ethyl 2,4-dioxovalerate and excavated significantly more tunnels compared to untreated sand, although this difference wasn’t seen in no-choice tests.

Trichoderma fungi under magnification
Trichoderma fungi have known fungicidal action against pathogenic fungi and appear to attract termites

Interestingly, the presence of ethyl 2,4-dioxovalerate in fipronil-treated sand caused the termites to spend more time in the treated sand and excavate more tunnels than in untreated sand (neither ethyl 2,4-dioxovalerate or fipronil). In addition, the presence of ethyl 2,4-dioxovalerate in fipronil-treated sand resulted in significantly higher mortality that in sand treated with fipronil alone. The authors suggest that further trials are required in different soil types to further explore the potential of ethyl 2,4-dioxovalerate to improve the performance of soil treatments, particularly with respect to insecticide transfer and increasing efficacy at low insecticide levels.

Impact of soil water levels on termite wood decay

With temperatures increasing and variations in rainfall patterns occurring due the changing climate, an increasing number of studies are looking into how various environmental variables impact termite foraging behaviour, particularly with regard to rate of wood consumption.

A five-year study in the US looked at wood consumption by termites in wetland forests.3 The study covered three different locations where the water level was generally at three different levels in the soil profile. The researchers compared the wood consumption at these sites to consumption in upland forests. Wood samples of three different types of wood were placed at three different levels in the soil profile – on the surface litter, at the litter/mineral soil interface, and in the mineral soil – and assessed annually (Figure 1).

Table showing level of damage in red maple wood placed at three different levels in the soil profile
Figure 1: Example data – level of damage in red maple wood placed at three different levels in the soil profile at wetland and upland (dry) sites

Wood consumption was lowest in the soils with the longest period of waterlogging and in the wetland areas, wood consumption was highest in the surface litter (51%) and lowest in the mineral soil (30%). Indeed, in the lower levels of these wetland soils, microbial decay rather than termite activity was the main driver of wood decomposition. In contrast, in the upland area, wood consumption was lowest at the surface litter (presumably due to low moisture and higher temperature), although wood consumption exceeded 85% at all three levels in the soil profile.

A recent study in subtropical forest in China produced similar results.4 Generally speaking, the warmer the temperature, the more wood was consumed. However, the level of moisture in the soil had a significant impact. While the general assumption may be that termites like moisture and therefore the more moisture the better, it ultimately depends on the drainage of the soil. In this study, wood consumption on the ridge top was maintained during the rainy season, where there was good drainage, but decreased in the valley, where the soil became waterlogged.

With changing weather patterns, the level of water tables and length of time soils remain waterlogged will impact termite foraging behaviour and wood consumption.

References

1 Lee, T.Y.H. and Phelan, P.L. (2025) ‘Reticulitermes flavipes (Blattodea: Rhinotermitidae) Response to Wood Mulch and Workers Mediated by Attraction to Carbon Dioxide’, Insects, 16(2). https://doi.org/10.3390/insects16020194

2 Javaid, W. et al. (2025) ‘Ethyl 2,4-dioxovalerate triggers aggregation and tunneling preference of Formosan subterranean termites (Blattodea: Rhinotermitidae) and enhances the effectiveness of fipronil’, Insect Science. https://doi.org/10.1111/1744-7917.13493

3 Adams, M.B. et al. (2025) ‘Wood decomposition in poorly-drained forested wetland soils: How important are termites?’, Soil Biology & Biochemistry, 204. https://doi.org/10.1016/j.soilbio.2025.109754.

4 Wu, D. et al. (2025) ‘Wood trait-decay relationships vary with topography and rainfall seasonality in a subtropical forest in China’, Journal of Ecology, 113(3), pp. 763–777. https://doi.org/10.1111/1365-2745.70006

Termite foraging behaviour research papers 2024

The effect of soil moisture on termite tunnelling behaviour

A key preventative measure to minimise termite attacks on buildings is to keep the soil around buildings as dry as possible. But how dry does it have to be to prevent termites tunnelling?

Researchers in the US assessed the foraging behaviour of two subterranean termites, Coptotermes formosanus and Reticulitermes flavipes.1 They looked at their tunnelling behaviour and survival rate in sand with varying moisture levels from 0% to 30%. Interestingly, even though they are quite different termites in terms of their nesting and foraging behaviour, there was no significant difference in the response between the species. At 0% moisture, the termites did not tunnel and did not survive. At 1%, the termites started tunnelling, but had died by the end of the 28-day study period. At levels between 5-30% moisture, the termites readily tunnelled with no difference in the tunnelling activity or survivorship between the different moisture levels.

The results reinforce the understanding that dry soils are a great way to minimise soil activity, but they do need to be very dry. Moisture levels as low as 5% would appear to be sufficient to allow active tunnelling (at least in these species). At the other end of the scale, termites appear to tolerate very wet soils too.

Termites avoid food marked with alarm pheromone

When foraging for food, for most animals, there is a risk vs reward trade-off. Namely, as the size of a food resource increases, animals may be prepared to take a bigger risk (increased chance of injury or death) to obtain it. This behaviour is not well understood in eusocial insects,
especially in termites. For the first time, researchers have investigated whether this foraging behaviour exists in termites by looking at Nasutitermes corniger.2

They evaluated combinations of differing quantities of food and intensity of pheromone alarm signal (with the varying intensity indicating differing levels of risk). Their results showed that termites avoid a food source if even a small amount of alarm pheromone is present, irrespective of the size of the food resource. This study would indicate that, for this species of termite at least, there isn’t a trade-off; these termites simply do not take any risks, avoiding a resource when an alarm signal is released. For pest managers involved in baiting, this emphasises the need to avoid disturbing feeding sites or bait placements, as this could result in an alarm signal being released and the termites avoiding the area.

Different termites have different tunnel foraging patterns

It has been observed in both Asia and the US that success with using in-ground bait stations for the management of the Asian subterranean termite, Coptotermes gestroi, is somewhat hit and miss. Indeed, in some studies, none of the in-ground stations were found by C. gestroi.
Considering the widespread use of in-ground baits to control C. gestroi, this is clearly an issue. But since in-ground bait stations have proven successful in the management of other Coptotermes species, the question is, why aren’t C. gestroi finding the bait stations?

Researchers in the US compared the foraging patterns of C. gestroi with C. formosanus, which regularly finds in-ground bait stations.3 The study demonstrated that C. gestroi produced longer primary tunnels and shorter secondary tunnels with minimal branching, whereas C. formosanus produced highly branched tunnels.

Termite tunnelling patterns
Coptotermes gestroi (A) and Coptotermes formosanus (B) have very different foraging patterns

The result being that in these studies, C. formosanus found significantly more feeding sites than C. gestroi. Whilst this observation could certainly explain why in-ground stations are not often found in the field, the researchers stressed the need for further research, as tunnelling patterns may vary by location (soil conditions, food source density) and also by age of the colony.

References

1 Richardson, S. and Sun, Q. (2023). Effects of soil moisture on tunneling, survivorship, and food consumption of the Formosan and eastern subterranean termites (Blattodea: Rhinotermitidae). Environmental Entomology. 52(4), pp. 539–545. https://doi.org/10.1093/ee/nvad049

2 Silva A.N.F et al. (2024). Food quantity and the intensity of the alarm signal combine to modulate the resource selection in a termite species. Behavioral Ecology, 35(1). https://doi.org/10.1093/beheco/arad086

3 Su, N. and Lee, S. (2023). A comparison of tunnel geometry between the Formosan subterranean termite and the Asian subterranean termite (Blattodea: Rhinotermitidae). Pest Management Science. 79(10), pp.3999–4003. https://doi.org/10.1002/ps.7594.

Further reading:

General information on termites

Termite predator avoidance:

How termites use sound to avoid predators?

Termites can hear ants coming!

How do termite hear predators?

Termite food choice:

How do termites decide which food source to exploit?

Termite cannibalism in starving colonies

Termites damage to plastic cables

Termite tunneling:

How do termites tunnel?

Division of labour during termite tunneling

Termites as structural engineers – How they stop homes collapsing as they feed.

Termite mud tubes:

Strange examples of termite attack

Choose Your Country or Region

Asia Pacific