Shining Guest Ant (Formicoxenus nitidulus)

Shining Guest Ant (worker)
Copyright: Neil Robinson

This tiny ant (3mm in length) lives inside the nests of larger wood ants. Hence, it has been termed a 'guest'. The 'shining' part of its name refers to its glossy black abdomen.

Unlike some other ant species that have been found in other ants' nests, the shining guest ant appears to be incapable of living independently without a wood ant host colony.

It lives in small colonies that construct their own nests within the host's nest. The guest ant seems to depend for its food on stealing from host workers as they exchange food items. The wood ants ignore their guests for most of the time but they have been observed to attack on occasion. The guest's response to aggression is usually to stay still, or, in rare cases, to sting the host (1).

Since it lives mainly within the host nest, the shining guest ant is seldom seen. On rare occasions, workers are observed on the surface of the nest. More commonly, it is seen in the autumn when the wingless worker-like males emerge to mate with the much scarcer winged females. If the host colony moves its nest, or establishes new nests, the guest ant moves with it.

Main Habitat(s): As the Southern Wood Ant

National Status

The shining guest ant has been recorded from all the main regions where wood ants occur in Britain, apart from north and west Wales and Northern Ireland. It is, however, less widely recorded than its hosts (possibly under-recorded due to the difficulty of seeing it) and is known only from about forty 10 km squares, which places it in the category of 'Nationally Scarce' (2).

Regional Status

In North West England, in addition to being present with the southern wood ant in the Arnside-Silverdale AONB, the shining guest ant is known to occur with the Northern Wood Ant in the Lake District (3). Despite a contraction in the range of the southern species, the northern wood ant has not shown any sign of decline, and therefore, the guest ant is probably not under any threat at the regional level.

Local Status

It has been recorded from Gait Barrow NNR on 16 wood ant nests in 1997. It was present in all the compartments in which the wood ant occurs, suggesting that it is present throughout the wood ant population (4).

It has also been found at Eaves Wood SSSI (5).

It is not yet known in Cringlebarrow and Deepdale SSSI, but there is the potential for it to be present as this is a site for the southern wood ant.

Current factors affecting the Species

The Shining Guest Ant is entirely dependent on its wood ant host. Since, in Lancashire, this is the southern wood ant, its conservation within the county depends on maintaining viable populations of this latter species.

Current Action/Mechanisms

See the equivalent section in the SAP for the southern wood ant.

Objectives, targets and proposed actions for shining guest ant in Lancashire

These are the same as for the southern wood ant (see its equivalent SAP) with the following addition:

Broad Objective:

A. Monitor the occurrence of the species with southern wood ant

Operational Objective

Action Required (Priority)




1. Determine the status of the species within the AONB.
1. Check for the presence of the guest ant at Cringlebarrow and Deepdale SSSI in 2001. (Medium)

EN, NT, Land-owners



2. Ensure that the occurrence of guest ants is investigated during monitoring for the southern wood ant [survey proposed in 2004 and subsequently every five years]. (Low)
EN, Land-owners


Links to other Action Plans: Broadleaved and mixed woodland HAP;limestone pavement HAP; southern wood ant SAP.

References & additional reading

1. Skinner, G.J. & Allen, G.W. (1996) Ants. Naturalists' Handbooks No.24.

2. BWARS (1997) Provisional Atlas of the Aculeate Hymenoptera of Britain and Ireland Part 1. NERC.

3. Robinson N.A. (1999) Observations on the "guest ant" Formicoxenus nitidulus Nylander in nest of the Wood Ants Formica rufa L. and F. lugubris Zetterstedt in 1998. British Journal of Entomology and Natural History 1 2, pp. 138-140.

4. Robinson, N.A. (1998) Observations on the "guest ant" Formicoxenus nitidulus Nylander in nest of the Red Wood Ant Formica rufa in 1997. British Journal of Entomology and Natural History, 1 1, pp. 125-128.

5. Alexander, K.N.A. & Collingwood, C.A. (1999) Pers com.

Date: April 2001.