From the plain reading of the story of Adam, Chava and the snake, it appears that the snake only communicated with Chava, not Adam.
Do any commentaries notice this and give a reason as to why this is the case?
Radak says two reasons.
1 - Since Hashem spoke to Adam directly, therefore the snake communicated with Chava.
כי לא היתה מצות האל לאשה אע״פ שאדם אמר לאשה מצות האל
2 - Since the snake felt it would be easier to convince a lady to do something wrong.
ואמר אל האשה ולא אמר לאיש, האשה קרובה להתפתות יותר מן האיש
According to Rashi to Bereishis 3:15, the serpent only spoke to Chava because was its intention to kill Adam assuming that Chava would give the fruit to him first and (after this) marry her:
ואיבה אשית: אתה לא נתכוונת אלא שימות אדם כשיאכל הוא תחלה ותשא את חוה, ולא באת לדבר אל חוה תחלה אלא לפי שהנשים קלות להתפתות ויודעות לפתות את בעליהן, לפיכך ואיבה אשית:
And I shall place hatred: You intended that the man should die when he would eat first, and you would marry Eve, and you came to Eve first only because women are easily enticed, and they know how to entice their husbands. Therefore, “I shall place hatred".
Although I haven't seen the exact question addressed, the answer is understood when reviewing several different details in the story of creation.
The essence of the idea is that the Nachash was trying to introduce doubt about what G-d had taught in order that sin might happen. This was not possible with Adam HaRishon because he had heard G-d's commandments directly.
In the case of Chava however, she had not heard the commandments directly from G-d, but only as Adam had taught them to her.
Originally, Adam and Chava had been one being in a single body, like the single, simple light of the first day of creation. That is what is referred to as Adam HaRishon, the aspect of Adam which pertains to the first day. But then, like with the creation of the two great sources of light from that original single light on the fourth day of creation, they were split into two beings. Chava's body was built from the tzela. Like with the two lights, one of those two was reduced and made to receive and reflect what it received from larger.
Adam's soul remained in the original body, the remnant of what existed originally. Chava's soul occupied a new body, built from a single element. This is the beginning of the concept of reincarnation (Gilgul HaNeshamot). When a soul is reincarnated into a new body, it generally does not retain knowledge and awareness of the prior incarnation. This is because what the soul perceives is filtered through the lens of the physical body it is dressed within. When that lens changes, perception and awareness is altered. It was for this reason that Chava became dependent upon Adam for her knowledge of what G-d commanded them to do and not do.
It records in Midrash that Adam taught Chava about what they could eat and not eat from the garden. Adam feared that Chava might make a mistake in regard to the tree of knowledge and because the consequence of transgressing this prohibition was so serious, added an additional restriction (סיג לתורה) which G-d had not commanded. That additional restriction which Adam added was not to touch the tree of knowledge.
Later, when the Nachash questioned Chava about what G-d expected of them, she repeated what Adam had taught her. And it was over that additional restriction that the Nachash introduced the doubt into Chava's mind about what exactly G-d wanted from them. The Nachash pushed Chava against the tree of knowledge and she discovered that she did not die from contact as she had been taught.