Also because in the English version they have on TV, they always refer to Pikachu as “it.” Ash’s crew does, as do the Rocket peeps. I remember b/c of how weird it sounds to refer to anything living as an “it.”
They’ve done it a lot. I haven’t seen the show recently (i.e. after the games started sexing the Pokemon), but from the earlier episodes at least, that’s how they spoke.
Why not? Don’t many plants produce sexually?
Pikachu: “I’ve got your Pocket Monster right HERE!!!”
Most don’t just pop out eggs, either. 
But yeah, I goofed. Sorry.
And yeah, they referred to Pikachu as IT and HIM in the English Version. Confusing, huh? That’s why it’s not a 100% accurate translation.
A Pichu (which will eventually evolve into a Pikachu) - a Pikachu and any other electric type (except, I think, another Pikachu - though I’ve never tested it, that should give a Pikachu) will give the pre-evolved form Pichu.
>>(chu is not a word, per se, but a perception of the sound a mouse makes, like we think a mouse makes the sound “Squeak!”).<<
Cool, thanks for the info Shawn. Not because it reveals secret mysteries of Pikachu I’ve always wondered about, but because it explains the title of “Chu Chu Rocket,” which is tons more interesting for me.
As was said, in Gold/Silver Gameboy versions, the species of pikachu can be male or female. In the cartoon, I’ve never seen a pikachu referred to as female, but I have not seen too many of the 'toons. IMHO, Ash’s Pikachu is a boy. I seem to recall the pronoun “him” being used, but I’m not sure. Anyway, Ash is too young to like girls (or at least admit to it).
FWIW, in the Gold/Silver Gameboy version inter-species breeding can occur (e.g., mate a ditto with a pikachu to beget a pichu or something like that).