周围敌对蚂蚁的存在不影响宽结兵蚁的数量，膨胀大头蚁Pheidole tumida 与宽结大头蚁Pheidole nodus 非常相似，目前不可能通过小型工蚁的形态来辨认两者，膨胀大头蚁Pheidole tumida 的兵蚁第一结节腹面具有一片状凸，宽结大头蚁Pheidole nodus 的兵蚁则不具有
原文：Pheidole tumida is similar to P. nodus. At present it is impossible to separate the two by minor’s morphology. However, the major of P. tumida has a very large lobate subpetiolar process. (Eguchi 2008)

在中国和南亚次大陆之间的物种中，宽结大头蚁可以通过以下的结合特征与它们区分开来：兵蚁正脸观相对较宽，后部凹陷较深;兵蚁头部背面长着稀疏且明显比background hairs（应该指的其它比立毛短的毛，比如微毛Microtrichia等）更粗的立毛;兵蚁额叶的后部、背部和侧面形成网状褶皱;兵蚁一般不形成腹柄下突或最多形成小隆突;兵蚁和小型工蚁的后结节较大。
原文：Pheidole nodus is distinguished among Indo-Chinese species by the combination of the following characteristics: in the major head in full-face view relatively broadly and deeply concave posteriorly; in the major dorsum of head sparsely bearing standing hairs which are much longer and distinctly thicker than background hairs; in the major posterior part of vertex and dorsal and lateral faces of vertexal lobe rugoso-reticulate; in the major subpetiolar process absent or at most present as a low carina; in the major and minor postpetiole massive.

平额大头蚁Pheidole planifrons
此种经常在出现在林地，在土壤中筑巢，很少在地面上的白蚁丘壁边上筑巢
原文：This species occurs from forest edges to rather woody habitats, and nests in the soil and rarely in the walls of termite mounds on the ground.
该物种与伊大头蚁Pheidole yeensis 相似，然而后者头后缘角形凹陷，且头顶具有明显横形凹陷，该物种的兵蚁与卡沷林大头蚁Pheidole capellinii 彼此相似，但二者之间的工蚁形态非常不同。
原文：This species is similar to Pheidole yeensis Forel. In the major of the latter, however, vertex in lateral view is strongly impressed in front of vertexal lobe; and frons is sparsely sculptured with longitudinal rugulae. The majors of this species and Pheidole capellinii are similar to each other, but morphology of the minor is very different between the two (see under P. capellinii).

在中国和南亚次大陆间的物种中，该物种通过以下特征结合被描述得很好：兵蚁的额基水平发育良好，部分突出触角窝;兵蚁的颊[昆虫的头壳以缝为界限由后向前划分为后头、头顶、额及唇基，两侧为颊。自复眼下方通至口上缝的两端，每侧各有一缝，称为颊缝(genal suture)，其后为颊(gena)。]长度远超眼睛（一般是复眼）直径的1.5倍;小型工蚁的额（头的正前方,上以蜕裂线侧臂、下以口上沟、侧以额颊沟为界;触角和单眼在此区）和头顶平整或粗糙（这里主要是想说自然观察有这对性状，或者说有不同的变异型，鉴别物种参考性有限）;小型工蚁的前后头（沿着头部的后外侧边缘）背侧横向突出明显;大型工蚁的后口区（位于上颚后头）中部和亚中没有突起;工蚁前中胸（还是上面我说的那个前中胸）顶的后坡耸起;小型工蚁胸部背部稀疏地长着短而粗的立毛，其顶有点截感（你可以理解成锥体被截成台体那种感觉，就是不像有的毛特别上尖下宽，这个顶部是稍微有点被截平的感觉）;大型工蚁第一节腹部背甲纵向完全或大体上有粗糙刻点。
原文：Eguchi (2008) - This species is well characterized among Indo-Chinese species by the combination of the following features: in the major frontal carina well developed horizontally, partly overhanging antennal scrobe; in the major gena much more than 1.5 times as long as maximal diameter of eye; in the minor frons and vertex smooth or shagreened; in the minor preoccipital carina conspicuous dorsally and laterally; in the major hypostoma without median and submedian processes; in the major and minor posterior slope of promesonotal dome with a mound; in the minor dorsum of mesosoma sparsely with thick and short standing hairs which is somewhat stubbed apically; in the major first gastral tergite longitudinally rugoso-punctate entirely or largely.

瑞亚大头蚁Pheidole rhea
该物种在高原和山脚下的山麓中被发现，海拔范围从1100米到2100米不等，他们显然更喜欢下者（应该是指2100米的地方）。根据Stefan Cover 的说法，它＂形成的巨大的群落，巢穴入口处像火山口一样，巢穴主要建在开阔的岩石陡坡上，这种蚂蚁大量收获种子，但他也是活跃的捕食者。成熟群落有不少分巢，大体型的兵蚁和超级大工蚁（supermajor 我们常说的特化）很少在巢穴外看到，该物种具有很强的攻击性，所有体型的分化（无论是工蚁还是各种体型兵蚁）都积极参与巢穴的防御。
原文：This species is found on plateaus and among foothills at the base of mountains across a wide elevational range, from 1100 to 2100 m, with an apparent preference for the lower end (Creighton 1950: 168). According to Stefan Cover (personal communication), it “forms enormous colonies surmounted by sloppy craters or under rocks, chiefly on open, rocky slopes. Seeds are harvested in large quantities, but the ants are active predators as well. Mature colonies have well-developed trunk-trail systems. Minors and medias forage, but large majors and supermajors are seldom seen outside the nests. The ants are aggressive, and all size classes actively defend the nest.” (Wilson 2003)
从上到下分别是不同体型的兵蚁，最上方是超级大工蚁supermajor，该物种的超级大工蚁据称能达到14mm以上，是世界已知最大的大头蚁。

这个物种在土壤中筑巢，而且巢穴可能非常大。它们在美国并不常见，在墨西哥更常见。兵蚁的头部太重了，以至于他们常常＂卡＂在一个姿势上：头部着地，身体和六条腿在空中踢。（应该是说它兵蚁头部太大了，摔倒后由于重心在头部导致无法重新爬起来）
原文：This species nests in the soil, and nests can be very large. They are not commonly collected in the United States, and are much more common in México. The majors have such heavy heads, that they become “stuck” in a position with the heads down and the remainder of the body and legs kicking in the air! (Mackay and Mackay 2002)m

瑞亚大头蚁Pheidole rhea是一个大型的多态物种，其中大型工蚁和小型工蚁的并胸腹节刺都非常长而尖。腹部前面连接后腹柄的地方是圆的。整个头背都覆盖着条纹，这些条纹向后外侧叶分叉。这些条纹可能在最大的工蚁的后外侧叶上形成同心螺旋。结节的顶端相对尖锐，在最大的工蚁中可能是双齿的。侧齿本质发育良好。
原文：This is a large, polymorphic species, in which the propodeal spines of both the major and minor are unusually long and sharp. The gaster is rounded anteriorly, where it connects to the postpetiole. The entire dorsum of the head is covered with striae, which diverge towards the posterior lateral lobes. These striae may form concentric whorls on the posterior lateral lobes of the largest workers. The apex of the petiole is relatively sharp, and may be bidentate in the largest workers. The lateral connules are well developed. (Mackay and Mackay 2002)
Also see the description in the nomenclature section.
该物种是少数具有三个工蚁亚品级的大头蚁属物种之一。
Gordon等人（2017）在一个大型（约30000工蚁）实验室群体中研究了三个工蚁亚品级之间的行为、形态和神经差异。他们发现：在敦硕大头蚁中，小型工蚁和兵蚁群体之间的行为和大脑解剖存在差异，但（普通）兵蚁和超级兵蚁之间没有差异。尽管可以通过体型和头部异速生长来区分三个工蚁亚品级（Huang和Wheeler 2011），但在行为和神经解剖学以及体型方面，兵蚁和超级兵蚁之间缺乏进一步的区别，这并不能为该物种中离散的、与体型相关的社会角色和神经表型的相关差异的选择提供证据。兵蚁和超级兵蚁之间广泛的行为技能重叠表明，这些规模级别的工蚁执行的任务在性质上并没有不同，而是可能在执行行为的频率、效力或效率上有所不同。如果兵蚁和超级兵蚁执行的任务在性质上相似，我们预计他们的感官、运动和认知需求也会相似，从而导致大脑表型的保守。
他们推测，这两个较大的工蚁亚品级专门用于处理和加工不同大小的种子。这些假定的行为差异在实验室群落观察的设计中没有得到解决。

上一段的原文：
This species is one of a small number of Pheidole species that has three worker castes.
Gordon et al. (2017) examined behavioral, morphological and neurological differences among the three worker castes in a large (~30,000 workers) laboratory colony. They found: differentiation in behavior and brain anatomy between minor workers and soldier groups but not between soldiers and supersoldiers in P. rhea. Although three worker groups can be distinguished by body size and head allometry (Huang and Wheeler 2011), the lack of further distinction between soldier and supersoldier groups in behavior and neuroanatomy, as well as body shape, does not provide evidence of selection for discrete, size-related social roles and correlated divergence in neural phenotypes in this species. The extensive behavioral repertoire overlap between soldiers and supersoldiers suggests that workers in these size classes are not performing qualitatively different tasks but may instead vary in the frequency, efficacy, or efficiency with which acts are performed. If soldier and supersoldier workers perform qualitatively similar tasks, we expect their sensory, motor, and cognitive demands to be similar, resulting in conserved brain phenotypes.
They speculated that the two larger worker castes are specialized for handling and processing different sized seeds. These putative behavioral differences were not addressed in the design of their laboratory colony observations.

卡沷林大头蚁Pheidole capellinii
该物种栖息于开阔的栖息地中， 比如耕地，并且在土壤中筑巢
原文：This species occurs in open habitats, such as annual cropping fields, and nests in the soil.

先知大头蚁Pheidole providens
于1835年被Sykes 描述，最初被分在芭切叶蚁属Atta下，四年后Westwood 建立大头蚁属Pheidole ，先知大头蚁Pheidole providens 成为大头蚁属模式种，Pashaei Rad等人（2018年）在伊朗中度降雨的山地地区采集了这种物种。
原文：Pashaei Rad et al. (2018) found this species in Iran in moderate rainfall montane areas.
说实话，作为模式种连标本图都没有，确实挺奇怪的

先知大头蚁Pheidole providns 的模式产地位于印度，没有模式图但后来绘制了，很可能是印度大头蚁Pheidole indica 的同物异名，在伊朗以前的记录中，很可能是特内里费大头蚁Pheidole teneriffana(印度大头蚁的次异名)
原文：Type location India, no type images but later drawing, and likely junior synonym Pheidole indica Mayr, 1879, type location India, major CASENT0906613, minor CASENT0906612. Probably among Pheidole teneriffana in prior Iran records

通过以下结合特征，这个物种在中南物种中很典型:工蚁头背非常短的平贴的背景毛中长着些许粗立毛;大型工蚁头部侧面观，额部头顶边缘强烈凸起;兵蚁额脊水平发育良好，部分突出于触角沟;小型工蚁的头背以及胸部的背面和侧面有刻点;大型工蚁和小型工蚁前中胸顶的侧面观中，其后坡有明显突出或隆起。
P. capellinii的兵蚁与平额大头蚁的相似，但易通过后文后者的特征区分开来:头侧面，额部头顶间的边缘凸起不明显;额叶顶和侧面呈网状;第一腹节背甲完全有粗糙刻点或不考虑后正中的有点磨光的部分。
Eguchi (2008) - This species is well characterized among Indo-Chinese species by the combination of the following characteristics: in the major and minor dorsum of head with a few thick standing hairs among very short appressed background hairs; in the major head in lateral view strongly raised at the border of frons and vertex; in the major frontal carina well developed horizontally, partly overhanging antennal scrobe; in the minor dorsum of head and dorsal and lateral faces of mesosoma punctured; in the major and minor promesonotal dome in lateral view with a conspicuous prominence or mound on its posterior slope.
The major of P. capellinii is similar to that of Pheidole planifrons, but is easily separated from the latter by the following characteristics of the latter: head in lateral view poorly raised at the border between frons and vertex; vertex and lateral faces of vertexal lobe reticulate; first gastral tergite longitudinally rugoso-punctate entirely or excluding somewhat polished posteromedian part.

棒刺大头蚁Pheidole spathifera
该物种兵蚁第 2 结节前下角突出呈小齿状，背面观近椭圆形；刺背面观末端钝，近棒状，轻度内弯（关于棒刺大头蚁Pheidole spathifera 的描述太少了，以后如果有再找到会补充）

奇大头蚁Pheidole aphrasta
该物种头形状奇特，头顶除横向凹陷外，两侧面还具斜向凹陷（说实话，感觉吧里面大部分标注为奇大头蚁的图片都与他的描述不太符合，这个物种也没有标本图，只有一张手绘图，吧里大部分所谓奇大头蚁的形态也并不太相似手绘图里的形态）

厚结大头蚁Pheidole nodifera
该种兵蚁第 2 结节明显膨大，宽为或约为第 1 结节 3 倍，具宽大的腹柄下突，第 1 结节两侧具粗脊，突出呈片状（我们常说的玛瑙大头蚁大部分就是厚结大头蚁的异色种）