Tetraponera penzigi is a species of ant of the subfamily Pseudomyrmecinae, which can be found in East Africa.

It forms an obligate symbiosis with the whistling thorn acacia (Vachellia drepanolobium), a dominant tree in some upland areas of East Africa.

[1] A worker of T. penzigi is typically 3.1 to 4.5 mm (0.12 to 0.18 in) in length and is black with light brown appendages.

[3] The whistling thorn produces a pair of straight spines at each node, and some of these have grossly swollen, hollow bases which are used by ants as domatia.

3-Octanone is also found as part of the alarm pheromone mixture of Crematogaster ants that are also symbionts on the whistling thorn acacia in Kenya.