To avoid alien abduction:

I don't mind the abductions and all that comes with it, but my scientist Sim has been abducted three times (and I've been spamming "prevent abductions" every time I remember and it lets me do so, which is why it's ONLY been three times) and impregnated every single time. I like alien kids, but man, that is WAY too much, especially since one of the pregnancies resulted in twins. I know we can send them back, but ... I'd rather avoid the pregnancies in the first place.

Ideally "prevent abductions" would premanently do that until you decide to "contact aliens" again, with the 24 hour cooldown being reserved for changing your mind.